EPISODE: 006 - STAGE 4 - TECHNICAL DESIGN

BYTNAR - TALKS

EPISODE 006 - STAGE 4 - TECHNICAL DESIGN

This episode is for people who want to know more about the process of project design and delivery.

If you ask yourself questions:

• What does this stage look like from the Architect's perspective?

• What does this stage look like from the Structural Engineer's perspective?

• What is the intricacy of the Structural Engineers' approach and why is there a stage 4.5 subdivision in the process?

• What are the perils of too precise definition and the perils of not enough information?

• Why do small projects up to 1 mil often never reach this stage or this stage is poorly delivered?

This episode should give you a broad idea of how the details in Architecture Engineering or Construction are arrived at if at all.

LET'S TALK ABOUT YOUR PROJECT

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This is Bytnar Talks – The Engineer Takes on Construction, Episode 6

Hi, I'm Piotr Bytnar.Each day I help my clients plan and design building projects through Bytnar Limited – a consulting Chartered Structural Engineers practice.

My biggest passion, and the cornerstone on which I've built my business, is finding clever solutions for construction projects. I am a Chartered Structural Engineer and a budding software developer, so you can rest assured that I will strive to talk about best practices and the use of new technologies in the industry.

And if you're embarking on a construction project or are involved in planning, designing, and building the world around us, you'll find this podcast useful.

This episode is about Stage Four of the Plan of Work – Technical Design.

[Music]

All right, guys, so here we are back at it again. Thanks a lot for tuning in. Another semi-wet week has passed in the beautiful land of Kent, and today I'm happy to add another episode on RIBA and IStructE Plan of Work 2020.

I am a little bit under the weather as I record this episode for you, so I hope it will not sound too snotty, and my weird noises and voices will not unduly impact your listening experience.

Just to quickly recap the last episode, where I told you about Stage Three of the project definition process:Stage Three involves the design team in fine-tuning the agreed blueprint from Stage Two, focusing on consensus-building towards the preparation for planning application, and identifying safety-critical elements and specialist items' designs, to name a few. It serves as a crucial phase for strategic planning, setting the stage for in-depth project definition in subsequent stages. But caution was advised on premature tendering at this point, as the overall goal of the stage is to solidify the shared vision for successful project delivery — not the production of sufficient design and specification for pricing.

Now we move to the stage where everything should be defined and tied together.

So, without further ado, let's get to it.

[Music]

Today I'll talk about Stage Four of the project delivery process — or framework, if you like. This is the sixth episode of the Plan of Work, a process which outlines the stages of a construction project: conception, definition, delivery, and operation, providing a structured framework for architectural and construction professionals.

Stage Four focuses on development design and preparation of design and specification information to enable construction. In this phase, the detailed design is refined based on the approved concept from earlier stages. Key considerations include technical specifications, regulatory compliance, and coordination with various specialists.

Stage Four lays the groundwork for the construction phase by creating a comprehensive and detailed plan that ensures the project’s successful execution and allows discharge of legal requirements of the design teams — things like Building Regulations, requirements of the Principal Designer (in the meaning of the Building Safety Act), or Construction (Design and Management) Regulations, construction-grade designs for Party Wall etc. Act 1996 considerations, and on and on and on.

The red tape is indeed vast, and I cannot even scratch the surface on it right here.

When I talk about Stage Four today, I'll talk about five different points:

1. I'll talk about the architect’s perspective — the architect's take on it.

2. Then I'll move to the structural engineer’s perspective.

3. In the next point, I will expand on the intricacy of that approach, and why indeed there is a Stage Four-and-a-half subdivision in that process, as defined by IStructE.

4. I will tell you about the perils of too precise definitions and the peril of not enough information as a result of this stage.

5. Then I'll talk a little bit about small projects (up to one million pounds), which often never reach this stage — or this stage is usually poorly delivered. But that’s the usual case in the smaller projects, where time equals cost, equals fees, equals the client approach: “No way I pay for this.”

So, not to faff about too much, let’s get to the main part of this material, shall we?

Let’s go.

[Music]

All right, so what do the architects do here?Well, the key activities of the architects in this stage are to develop a detailed design. We need to further refine that architectural, structural, and building services design, and assure it all comes together in minute detail.

We develop detailed plans, sections, and elevations of the entire building and its parts to assure it all comes together — and to assure that it’s all coordinated and all of the other specialisms — specialist designs — are included within that coordination. We need that input from the contractors to make the one whole that speaks one truth — that design that speaks one truth.

The buildings are very complex, and you know, there's plenty of specialist systems that may be incorporated within such a building. And with all of those special technical information — technical design — and its placement within the building, it needs to be coordinated and placed on the final designs.

This is the time where the detailed technical specifications — outlining all of the materials, finishes, and construction methods — are being tied together to deliver information for construction, integrating all of the aspects, including sustainability and energy efficiency measures.

This stage is to show the regulatory compliance — to show that the building indeed covers all of the Building Regulations aspects of it, and has been approached wholesomely, and that it is now ready to be taken forward for construction.

The usual process is to go for plans approval with your building regulator — with your building control, whether private or council.

The architects, as well as coordinating all of the specialisms — all of the different aspects of the building project — are now to also check on the costs of the delivery of the whole project, to assure that it's actually still within reason and can be sent for tendering. They need to update the budget wherever the actual cost goes over it — or maybe under, however that's very, very rarely the case.

But anyway, where we’re going here, we need to identify the budgetary issues that may need to be addressed, and that may need to be communicated to the client.

What’s the output of this stage?

It’s comprehensive technical drawings that include all of the plans, elevations, sections, minute details, detailed technical specifications of all of the elements and their costs, as well as all of the required approvals of statutory bodies and issuance of statutory forms, if the building is large enough to involve the Health and Safety Executive. We need to ensure the coordination of all of the different disciplines has taken place.

We need to address any issues that have been identified when we look at the project in more detail. We need to assess risks and combine them into information for everyone that will be taking part in the execution and the use of this building. And wherever possible, we need to mitigate those risks — if they cannot be removed from the process.

We need to think about health and safety during the construction of the build — trying to find the easiest and the safest way for the erection of the building.

Obviously, we engage the client at certain points where their input is required, and to assure that the employer’s expectations are met.

All of those documents — all of that information — needs to be gathered to be able to transition to Stage Five, and to take the design into the tendering stage, or give it to the design-and-build contractor who will develop it further.

In any case, very often this stage overlaps with Stage Number Five, especially on the bigger projects, when you want to start as quickly as possible and not all of those details can be ironed out before you can start. But nevertheless, a staged approach should follow — where one stage is closed, and one stage is begun on-site, while the next stages are still developed. So we don’t start a stage unless all of the information is already present and we can carry on with the build.

What do engineers do in this stage?

They ensure that the design is developed to its final detail, and that all the required information is coordinated in detail with architectural aspects and layouts and buildups of all different elements.

Engineers will lead and coordinate with specialist designers, making sure that everything fits well together, and that all the considerations for the design of the main structure are still viable for the specialist input — or whether their design is correct for the specified performance and behaviour.

You know — things like cladding, glazing, balustrades, steel and concrete connections of main elements, but also auxiliary elements.

The developed design needs to discharge the Building Regulations: safety, durability, robustness, fire considerations for the building. All elements should be dimensionally set out and shown on design documents to check for and reconcile any clashes, if such reveal themselves. Very often, it would be prudent to have a strategy for the development of temporary works, so the contractor has an indication of how it all should be done — on how we think of delivering the project. Or even if, you know, we send the package for temporary works to a designer who's separate from every other person, it would be good to show that intent — so the actual temporary works designer knows how you plan to deliver the building, including a rough draft of a construction phase plan.

It doesn’t have to go down to all of the nitty-gritty details of it, but we should know how and what will be needed. If you don’t have that, everyone works a little bit in the fog — and yeah — everyone will charge for that uncertainty, right?

If we need any local beefing up for the construction operation of the temporary or the permanent structure, as such may be the case sometimes — maybe we need a crane base, or maybe we can use a climbing crane in the core, or otherwise support it on the side of the building. Maybe the site is constrained, and the structure will need a little bit of beefing up to allow heavy machinery and deliveries to drive through the building. And maybe you can have a few storeys used as parking and delivery space for the site operation, which then will change into typical use — but for temporary conditions, will be needed as a loading bay.

You see, all these sorts of aspects — if they can be thought about at this stage — we avoid unnecessary delay and unnecessary further consideration down the project timeline.

Right. You see, even at that point, as an engineer who designs these types of schemes — designs buildings in their intricacy, in the intricate details — engineers divide Stage Four into “Four” and “Four-and-a-Half.”

Why?

Why they do that is simply because the amount of information that will be required by a contractor may not be known at that point — or indeed, isn’t known at that point. And we don’t know who will be the actual contractor and what are his or her capabilities.

Therefore, we cannot provide IKEA-style designs that will show this contractor how to assemble every single bit — part by part, step by step — as that’s not the responsibility of an engineer or an architect or any other designer. It’s the responsibility of the contractor to take the designs on board, assimilate them within their practice, and deliver it to the level of expertise that they have on board.

So, even if all the technical designs are delivered by the structural engineer, there will still be aspects to reconcile — either with the manufacturers, contractors, or fabricators.

The importance of Stage Four-and-a-Half is to provide the actual specific information for all parties to construct from — things like size, length, position, amount, location (length — I think I’ve mentioned that already) — of reinforcement details, fabrication shop drawings showing all elements (whether that be timber, steel, or whatnot), review or preparation of the contractor’s method statement to show no undue impact is placed on the structure, or that it remains stable and safe during construction.

We’ll be reviewing or preparing temporary works designs for the contractor.

This is the stage when the contractor is employed for the execution of the work — when his capabilities may require more or less of the engineering team’s involvement. It is also prudent to have quality assurance from the structural engineer here — to assert on the correct interpretation of the information by the contractor, and to assure that the correct delivery of the designs is actually in place.

So that would be Stage Four-and-a-Half — that’s why it’s there.

Sometimes at this stage, some architects and engineers — mostly inexperienced, but often highly skilled and methodical ones — push for overly meticulous and detailed designs, showing dimensions of elements down to the tenth of a millimetre.

In reality though, such accuracies are fallacies. And at the scale of buildings — if you take the scale of a building — they’re not achievable.

After all, we do not design and construct Swiss watches, but super heavy and large structures. Whether the building is made of masonry, steel, concrete, or wood — the size of the element can vary a few millimetres in one way or the other, and can be out of plumb and not square. Slightly warped materials ain’t perfect — the execution’s neither.

So as long as it is within certain limits, of course — we’re good to construct such a building.

But it’s, we need to acknowledge that these sorts of limits do exist, and these departures from true straightness, true square, and plumb expectation — this is how buildings are. This is how the construction game is.

If you build tall buildings and load the elements as you go and erect next — you know, floor after floor — the columns become loaded more and more. Therefore, they become shorter and shorter. Well, you need to think about this movement. So, you need to make those columns a little bit longer so they can become shorter, but be in true with the intention when you erect the whole structure.

You see, the elements and structure change shape between day and night, or between wet or dry seasons. Millimetre precision is not possible, and designers should think about these inaccuracies — or how the building will behave as it is being built — not be idealists.

You see, paper will take everything — we like to say that in the industry. Whatever you write, whatever you draw — paper will take it all. And it's indeed correct. But in truth, buildings aren't perfect, and how they are assembled together isn't perfect.

In my practice, I often find plenty of rework just because the designers thought that buildings come together as drawn — either not allowing for adjustments in their technical design, or not remeasuring elements as they’re being built.

I trust it is generally more economical to have a site engineer measure stuff up prior to fabrication or commencement of the next phase, rather than to rework elements on site or send them back to the manufacturer for redoing.

The other peril is the often-attempted strategy by designers to put all the detailing, design, fabrication, construction drawings — sometimes temporary works designs and so on — solely on specialist subcontractors: steel fabricators, concrete or timber contractors, stonemasons, or whatever.

This way, engineers and architects can avoid risk with reworking, remeasuring, coordination — but on the other hand, all the fabricators are not incentivized to make these details cost-effective. They are incentivized to make them easy to do and labour-intensive — so they can charge more for their service. It is only human nature.

And the cost of pushing the work and responsibility down the supply chain isn’t the greatest and most economical thing to do.

In Bytnar, these times — clients are our bread and butter, you see — there is not enough expertise or appropriate personnel in many of such steel, concrete, or timber contractors' offices.

It only makes sense to employ a senior, independent engineer if the amount of such work hits five to ten million pounds, and the office already spends around £100K on external engineers to provide them with appropriate designs and indemnity cover.

So far, we are very happy at Bytnar to provide such specialist services for our trusted contractors, and we are delighted when our designs are delivered smoothly — as we provide that definition as a standard service for all our appointments.

This brings me to point five of my deliberation — the point where I’d like to tell you about those small projects, sometimes projects up to £1 million, sometimes even beyond, which often never reach this stage, or the stage is poorly delivered.

You see, clients at this level of fees — which need to be charged — it's our time. And time equals cost, and cost equals fee. But the clients see the amount of required fee level — and they cannot justify it plainly, as they’re usually not educated in the art and science of project delivery. And that’s very often the first and last project they ever do.

So, the usual approach to the fees of professionals is: “No way I’m paying for this.”

You see, it is all too often an expense that projects with a contract value under £1 million are delivered hastily, without in-depth consideration of many aspects — in a way, being pushed down the process, with plenty of angst between the involved parties and lack of appreciation of the actual process of project definition, or the scope of the required deliverables.

These projects are, by far, the most common products available on the market. So all small offices compete for them.

Small offices are often cut off by the requirements of the public frameworks and the competition of industry multinationals — from the better-defined and better-financed, more sustainable projects. So, they cut corners. They cut services. So the processes are never — very rarely — well defined.

All to the fire adds the fact that the British building regulation system does not require any particular licensing of, or proof of competence to embark on planning permission or building construction. Anyone can build anything, and maybe at some point there will be repercussions. Even the latest addition of the Building Safety Act protects the higher-risk buildings — not construction in general. Provision of competency requirements for this consultation and deliberation is not enough of a deterrent to stop incompetent people from certifying themselves as competent — until proven otherwise.

So, we end up with anyone who can draw a few lines on a piece of actual or electronic paper sending planning applications for houses, extensions, and layouts of buildings that are ill-defined and often require later resubmission for changes — as it transpires that the people who drew them did not consider Building Regulations in enough detail, or structures defined by anyone who has “seen one before” and copied and pasted, or used software or an Excel spreadsheet downloaded from Reddit.

I know — it all seems silly, and you would wonder, “Is that even possible?” But that's the type of project that is prevalent. You can just go on any council website and go through the planning permission system, and you'll see — 70% of them are done this way.

And yeah — that figure is from thin air. It's not something that you— yeah, don’t— don’t hold me to it, okay? But there’s a lot of them there, and there are a lot of these mistakes that land on my desk as well — with people in distress that need help when the contractor is already on site and cannot deliver the building.

In my office, for starter projects of up to and around £1 million contract value, we charge about 7.5% of the contract value for the Stage One to Four definition — and that’s for architectural services — and another 2 to 2.5% for structural and civil engineering services.

You see, that’s £75,000 for architectural services and £20,000 for engineering services. Trust me when I tell you — £95,000 before the shovel is in the ground — for most first-and-last-time property developers, seems extravagant. And they will avoid it as much as possible.

When a similar amount will be used instead for bad work — fragmented and stressful work — down the project line. But that cost is hidden. Trust me, no one will go back to say, “We should have defined it well from the word go.”

No — all will push to finish the project at whatever cost. But there’s no other way, right? We need to finish the project, however bad it is and however wasteful it—

[Music]

Okay, so this is it for today. Let us summarise the above points:

1. From the Architect’s Perspective

Stage Four involves detailed design development — refining architectural, structural, and building services designs.This includes:

• Collaboration with specialist consultants

• Integrating technical specifications

• Ensuring regulatory compliance

• Monitoring costs

Outputs from this stage include comprehensive technical drawings, detailed specifications, updated cost information, and regulatory approvals.

Key considerations involve coordination among design disciplines, risk management, and client engagement.Successful completion of Stage Four paves the way for Stage Five (Construction), with a detailed set of documents ready for the construction phase.

2. The Structural Engineer’s Role

The structural engineer’s role involves meticulous coordination with the architect and specialist designers to ensure final design details align seamlessly.

This includes addressing:

• Cladding

• Glazing

• Balustrades

• Connections of main and ancillary elements

The developed design must meet:

• Building Regulations

• Safety, durability, robustness, and fire considerations

Dimensional layouts are carefully examined to identify and resolve clashes.

Additionally, a strategic approach to temporary works development is considered — assessing the need for:

• Local reinforcements of permanent structures

• Requirements for crane bases

• Structural modifications to facilitate construction operations

The engineer’s perspective encompasses a comprehensive evaluation of all elements to guarantee structural integrity and a successful project outcome.

3. Importance of Stage 4½

Despite technical designs being completed, collaboration with manufacturers, contractors, and fabricators requires additional intricacies.

This stage includes specific details such as:

• Reinforcement size, length, position, quantity, and location

• Producing fabrication shop drawings

• Coordination of temporary works

• Review or preparation of contractor’s method statements

• Ensuring no undue impact is placed on the structure and it remains stable during construction

It also requires flexibility based on the capabilities of the contractor and fabricators involved. Stage 4½ bridges the gap between design completion and actual build execution, providing practical, buildable, and risk-aware documentation. Additionally, the review or preparation of contractors’ method statements and temporary works designs ensures that construction does not compromise structural stability and safety during construction. As the contractor is engaged for execution, the level of engineering team involvement may vary based on the capabilities of that contractor.

Quality assurance measures from the structural engineering team further ensure correct interpretation and accurate delivery of designs during this critical construction phase.

Point Four

The perils of overly precise design include unrealistic expectations of millimetre accuracy in building construction, leading to site rework due to unavoidable variations. Building elements can fluctuate in size and alignment due to factors like weather, temperature, and construction processes.

Furthermore, relying solely on specialist subcontractors for detailing, fabrication, and construction stages can also be problematic. While it may alleviate some risk for architects and engineers, it often results in less cost-effective solutions, as subcontractors prioritize ease and increased charges.

Point Number Five

Small projects with a contract value under £1 million often struggle to reach — or poorly deliver — Stage Four of the RIBA process due to time, cost, and fee constraints. The competitive nature of small project bidding, combined with limited access to public frameworks and industry giants dominating the realm, puts pressure on smaller offices.

The lax British Building Regulation system, lacking licensing or proof of competence, allows anyone to undertake planning or construction without stringent requirements — further driving down quality and price.

So this is it, folks. I hope you’ve enjoyed it. I hope you found something useful for yourself.

This is the end of the main body of this podcast — now let’s move on to a few words from me, shall we?

[Music]

I always like to end with a couple of words from me, but if you’ve already got enough — this is the place where we can shake hands.But if you want to know more, please stay tuned for another minute or two.

I love to deliver projects and services at all different stages of project design and to all different levels of detail and definition.

Bytnar Limited — evolved from being capable of providing in-depth, specialist-level design definition, bridging Stages Four to Five for projects of different sizes, but often for projects of £1 million and below — we then incrementally grew in experience from the detail to the concept.

You could say: I feel the design and construction viscerally by now.

Anyway — we enjoy helping our clients deliver often ill-defined designs when they hit the wall of lack of information, or not-so-realistic information, and do not want to go back to their architects or engineers — as the trust is, by that time, well stretched and eroded... or simply gone.

How things are delivered in Bytnar — no matter the project size — we go through the process and improve on it with every iteration.

We’ve concluded, by now, over 400 different projects of different sizes, from a single beam to consulting on high-rise buildings built over existing buildings.

Sounds interesting, doesn’t it? And sounds complicated, too.

Whether they are projects with a contract cost of £50,000 to £250,000 — they will require a different level of involvement than the ones costing £1 million and over.

We balance the requirements, expectations, and safety to deliver enough information depending on your budget and project scope.

Our service is bound by a process to make the most of the time and cost expected to be spent on the design and its definition — but we will never accept a commission that is not well communicated with you in regard to the scope of deliverables.

If your design budget is not sufficient — we will tell you straight up and we’ll explain why.

But we will not take on a commission which we know will not pay well — for both sides, and for your project.

So here we had it — the Technical Design, or Stage Four — the point in the process where details are delivered and the project becomes ready for construction...But not always.

If you struggle on your projects, or do not understand what it is your current architect or engineer is doing — we can help.

Thank you for listening.Please voice up your opinion — I wait for you on LinkedIn, and I want to hear from you.

Toodloo!

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Piotr Bytnar BEng (Hons) MSc CEng MIStructE

Chartered Structural Engineer who deals with the Architecture of buildings. His Master's Studies led him to an in-depth understanding of risk and contract arrangements in construction as well as specialist knowledge in soil mechanics.

He and his team help homeowners and property developers to design and deliver construction projects reducing waste in time and the cost. He believes that the construction project is an iterative process that can be well managed and it is best managed if all the aspects of the project definition and management are dealt with in-house or coordinated by one organisation. His team works to all stages of RIBA and ISTRUCTE stages of work and enables contractors to deliver projects on-site providing risk evaluations, methodologies for execution of works and temporary works designs.

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