Adapting a ready-made project to timber-frame technology – is it worth it?
What does converting a masonry project to a timber-frame one involve?
Many investors think that adapting a project is a simple cosmetic procedure – crossing out the word "hollow brick" and writing "C24 wood". In reality, it is a much more complicated process, more akin to translating poetry into programming language than a simple word-for-word translation. Masonry and timber-frame technologies differ fundamentally in the way they transfer loads.
We are increasingly carrying out timber-frame houses in Małopolska, a great example of which is our project in Lanckorona. Timber-frame technology will work well where investors have difficult, mountainous plots and are looking for light and fast construction technologies. In a masonry house, every load-bearing wall is a massive element that continuously transfers the weight of the ceiling and roof. In a timber-frame construction, we are dealing with a point (columns) and frame system. When a conversion of a masonry project to a timber-frame one is commissioned, the structural engineer must recalculate the statics of the building from scratch. It is not enough to change the thickness of the walls. It is necessary to design new stud spacings (usually every 40 or 60 cm), select the appropriate cross-sections of lintel beams, and, crucially, adapt the roof truss to the lighter, but differently working, wall structure.
Another aspect is spatial rigidity. A masonry house is rigid by nature of its mass. A timber-frame house requires the design of appropriate sheathing (e.g., with OSB or gypsum-fiber boards) and wind bracing, which ensure that the building does not "collapse" under the influence of strong wind. Therefore, adaptation is in practice the creation of a structural design from scratch, based only on the form and functional layout of the original.
Project adaptation, how much does it really cost?
Costs are usually the main motivator when choosing a ready-made project. A project from a catalog usually costs from 4 to 6 thousand zlotys. This seems like a bargain compared to an individual project, which can cost 15–25 thousand zlotys (and more). However, the math changes drastically when the phrase comes into play: project adaptation price.
You must realize that the architectural office selling a ready-made project rarely agrees to make structural changes for the price. You receive consent for changes, but the physical adaptation must be done by a licensed designer or structural engineer, whom you will hire on your own or the construction company will do it.
The cost of such an adaptation includes:
- A new structural design (structural industry) – this is the biggest cost, often amounting to 5,000 to 10,000 PLN depending on the complexity of the form.
- A new design for plumbing and electrical installations – in a frame, they are run differently than in a wall (inside the walls, without chasing grooves), which requires precise planning at the design stage.
- Adaptation to the plot (a standard cost for any construction).
In total: 5,000 PLN (project purchase) + 8,000 PLN (timber-frame structure) + 2,000 PLN (installations) = 15,000 PLN. We are approaching the amount for which you could order an individual house project, tailored perfectly to your needs and the specifics of the technology, without the compromises resulting from alterations.
You gain a free room
One of the most powerful arguments in favor of timber-frame technology, which is often forgotten by investors who only look at the price of the project, is the usable area. This is where timber-frame technology shows its gigantic economic advantage, which often pays back the adaptation costs with interest.
Let's analyze this with a specific example. A standard wall in a modern masonry house, meeting the WT2021 standards, is about 25 cm of structural material (hollow brick, silicate) plus 20 cm of styrofoam. Together, this gives a wall thickness of 45 cm. In a timber-frame house, to achieve the same (and often better) heat transfer coefficient, a wall with a total thickness of about 25–30 cm is sufficient. This is because in a frame, the thermal insulation is inside the wall structure, not just on the outside.
The difference is on average 15–20 cm for every linear meter of external walls. In a house with a building area of 100 m² (e.g., a one-story house 10x10 m), the perimeter is 40 meters. So we gain about 6 to 8 square meters of usable area while maintaining the same external dimensions of the building. This is the size of a decent bathroom, a dressing room, or a small study. At today's construction prices (approx. 5-7 thousand PLN per m²), you gain "free" space worth up to 40,000 PLN.
Changes in a ready-made project – what is easy and what ruins the budget?
Investors often assume that since we are redrawing the structure anyway, we can change everything at the same time. Yes, we can, but changes in a ready-made project are divided into cosmetic ones and those that destroy the economic logic of adaptation.
Simple and cheap changes in adaptation to a frame include:
- Moving partition walls (as long as they are not a bracing element of the structure).
- Changing the location of internal doors.
- Changing the size of windows (within reason, without creating gigantic glazed areas requiring steel frames).
- Changing the type of facade (e.g., from plaster to board).
Changes generating high costs and problems:
- Moving load-bearing walls – requires a complete recalculation of the roof truss and foundations.
- Changing the roof pitch or type of covering (e.g., from metal to heavy ceramic tiles) – drastically changes the loads.
- Adding a garage or carport to the building's form – this is basically designing a new part of the house.
- Changing the location of the chimney or plumbing risers – collisions with floor joists in a frame are harder to get around "on site" than in a wall.
When deciding on a ready-made project, you have to accept it 90%. If your wish list starts with "I like this house, but...", it's a sign that you should consider an individual solution.
Case Study. Why doesn't the factory like catalog designs?
Modern timber-frame construction is often prefabrication – the walls arrive at the construction site ready, with windows and insulation layers installed. Companies that produce houses in this way operate on modular grids. Production optimization consists in making the dimensions of the house a multiple of the standard dimensions of the panels (e.g., 1250 mm or 2500 mm). This allows for minimizing waste.
Ready-made projects, drawn for masonry technology, rarely adhere to these modules. A wall with a length of 10.80 m in masonry technology does not generate a problem – you simply cut the hollow brick. In timber-frame prefabrication, such a dimension can generate a huge amount of waste of expensive structural timber and sheathing boards, for which the investor will pay. What's more, the specific "ornaments" of masonry architecture – bay windows, complicated dormers, rounded walls – are difficult to execute in timber-frame technology and disproportionately expensive. Adapting such a project is often a struggle with the material, to fit an "analog" project to the "digital" precision of the factory.
| Feature | Ready-made Project (Adapted) | Dedicated Project (Timber-Frame) |
|---|---|---|
| Fit to panel modules | Low (a lot of material waste) | High (minimized losses) |
| Installation optimization | Requires redesigning routes | Designed in the walls from the start |
| Preparation time | Long (adaptation + changes) | Medium (designing from scratch) |
| Risk of errors on site | Medium/High (unusual details) | Low (system details) |
| Total documentation cost | 10,000 – 16,000 PLN | 15,000 – 25,000 PLN |
Individual house project
There is a critical point where saving a ready-made project no longer makes sense. An individual house project becomes a necessity (and a saving!) when your plot is unusual. A narrow plot, an entrance from the south, a large slope – ready-made projects are usually created for "ideal plots". Forcing a typical project onto difficult terrain ends with expensive earthworks and a non-functional interior layout.
When designing a timber-frame house from scratch, an architect collaborating with the contractor (or engineers from our office – check the about us tab) optimizes the structure in terms of costs. They can design floor spans to use standard beams, not expensive BSH glued laminated timber. They can arrange the windows to fit in the modules between the studs, eliminating expensive lintels. In an individual project, you pay for the house to be cheaper to build, not just pretty on paper.
Speed of construction – the myth of adaptation vs. reality
Clients choose ready-made projects because they want to build "now". It seems that buying a "ready-made" will speed up the process. In the context of timber-frame technology, this is often illusory. The process of industry adaptation (structure, installations) takes from 4 to 8 weeks. During this time, the contractor must repeatedly consult with the investor about details that were not important in the masonry project (e.g., the exact location of reinforcements for hanging kitchen cabinets – in a frame, you need to know this in advance).
For comparison, creating a concept and a building project dedicated to a frame usually takes 2–3 months. The time difference is small, and the quality of documentation created from scratch for a specific technology is incomparably higher. More importantly, good documentation means fast prefabrication and assembly. Errors in the adaptation of a "ready-made" come out on the construction site, causing downtime, which is the most expensive element of any investment.
Energy balance and thermal bridges
Masonry projects often contain architectural details that are difficult to insulate or in a frame generate thermal bridges if they are not thoroughly thought out. An example is cast-in-place (cantilever) balconies, which are standard in masonry, and in a frame require complex steel-wood constructions so as not to cool the ceiling. When adapting a project, you often have to give up certain solutions in favor of those that are more energy-safe – e.g., replacing a balcony with a self-supporting structure attached to the building.
Another aspect is acoustics. The ceilings in masonry houses are heavy and dampen impact sounds well. In an adaptation to a frame, where the ceiling is lighter, it is necessary to design appropriate weighting and soundproofing layers. If the adapting designer "only recalculates the beams," you may end up in a house where you can hear every step on the first floor. This is a nuance that is not visible on the drawing, but which determines the comfort of living.
When is it worth adapting, and when to run?
I don't want to completely discourage you from adapting. There are situations where converting a masonry project to a timber-frame one makes sense. This happens when:
- The chosen house has a very simple form (rectangle, gable roof).
- You are not planning any changes to the functional layout.
- You care about a specific facade appearance that you haven't found in the offer of modular companies.
- You have a trusted structural engineer who specializes in timber frames.
However, if your dream project has a complicated multi-pitched roof, dormers, columns, and unusual bay windows – adaptation will be a torment, and the cost of execution in timber-frame technology may exceed the cost of masonry. Timber-frame technology loves simplicity – modern barns, simple forms, large glazed areas. This is where it reaches the peak of its price and energy efficiency.
Strategy for the investor
The choice between adaptation and an individual project is a strategic decision. If you have found a ready-made project that is a "simple barn" and suits you 100% – adaptation will be profitable, especially considering the gain in usable area. However, if the project requires many changes, has a complicated form, or does not fit perfectly on the plot – invest in an individual project. The money spent on a good architect and structural engineer will pay for itself in a cheaper construction, less waste, and a house that works like a precise machine, not an assembly of mismatched parts.
