Tai ar y Cyd 2B4P - Can one timber frame work for different site layout configurations?

In a previous blog, "Tai ar y Cyd – Did We Need to Change the House Types?", we shared why we made the TAYC 2B4P house deeper front to back to match the TAYC 3B5P house type for terrace configurations for our planning submitted project at Nant Y Coed, Llandudno Junction with Cartrefi Conwy.

This change made coordination easier, and gave both popular family homes the same structural depth.

Having completed that exercise, we asked ourselves another question.

If we want to truly industrialise the delivery of the TAYC house types, can every 2B4P home use the same timber frame, no matter if it's semi detached, handed semi detached or terrace?

We're not talking about changing the house design. It's about reducing manufacturing differences. If a factory can keep making the same timber frame for any location in a development, production gets simpler, buying materials is easier, and quality stays consistent. If the site is delayed, the frame could be used in a different location on the site, or if a project is delayed, the manufacturer could even transfer it to another project.

That is exactly the philosophy behind a real kit-of-parts approach.

Option 1: The Original Tai ar y Cyd Proposal

This option sets the benchmark.

A handed pair of semi-detached homes works just as it was first designed.

• Adopts TAYC baseline external wall and party wall build ups ( 219mm ext stud ).

• The external envelope works to brickwork setting out.

• The external wall cavities are 75mm.

• The party wall cavity is 50mm.

• No changes are needed.

  
  

Option 2: Non-Handed Semi-Detached. The first challenge comes when two primary orientation dwellings are placed together.

The interior layouts, and therefore the timber frame, remain the same, but the brickwork no longer courses.

To make this setup work, the party wall cavity has to increase from 50mm to 135mm, and the right-side external cavity has to increase from 75mm to 103mm.

Option 3 – Three Unit Terrace (end plot handed). This option shows that a terrace can also use the same timber frame.

The external wall cavities stay at 75mm, while:

• the cavity between Plots 1 and 2 goes up to 135mm, and

• the cavity between Plots 2 and 3 stays at 50mm.

  
  

Again, the difference is handled in the cavity, not by changing the timber frame.

Option 4: Three-Unit Terrace (Non-Handed)

To keep the brickwork and timber frame dimensions the same:

• The party wall cavity goes up to 135mm on both party walls, with a 103mm cavity to the right-hand gable.

Option 5: Refining the Party Wall

Our last option looked at a different question.

Instead of sticking with a 135mm party wall cavity, could we improve the party wall build-up itself?

By reducing the service void in the party wall from 50mm to 25mm and swapping the 15mm SoundBloc lining for 12.5mm plasterboard, the required cavity widths drop to:

• a 77mm cavity between Plots 1 and 2,

• and a 105mm cavity between Plots 2 and 3.

  
  

What have we learned from this?

There are two options.

Option 01 - make different timber-frame versions to fit each layout.

Option 02 - keep the timber frame the same and let the cavity widths change to adjust for different configurations.

From a timber-frame manufacturing perspective, the second option seems more in line with industrialised construction principles.

If the factory keeps making the same timber frame, it’s easier to control quality, simplify procurement, and improve efficiency. The masonry contractor can then handle the differences by making small changes to the cavity width instead of needing a different timber frame.

If Tai ar y Cyd is intended to evolve into a genuine kit-of-parts housing system, should we be fixing the timber frame and allowing the cavity widths to vary?

If the objective is to manufacture thousands of homes as efficiently as possible, standardising the timber frame seems worth exploring.

If you were running the the timber frame factory, what would you rather manufacture?

Different timber frames...

...or one standard frame repeatedly?