Damp proofing

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  • Building design and specification - Architectural designer 
  • Product and system specification - contact a manufacturer for advice

Make sure to install waterproofing membranes as per the manufacturer’s guidance. Specify, where possible, one company’s product suite, getting their specification advice ahead of time. Check for a system warranty, rather than a product warranty. That way, if there are any issues with the performance of the waterproofing products, it can be clearly addressed by the manufacturer/installer. 

Damp proofing

The same as with any typical timber building, adequate damp-proofing will be needed at ground level to stop moisture from the ground getting into your building. We already know we have to lift the WikiHouse structure and any timber sole plates up and out the ground by at least 150mm. Damp proofing will need to be installed below the WikiHouse frame and integrated into your substructure design. 

The damp proof layer should lap up and over some of your breather membrane, ensuring there is a continuous waterproofing layer. 

Breather membrane

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  • Building design and specification - Architectural designer
  • Product and system specification - contact a manufacturer for advice

A breather membrane stops moisture from the outside getting into your wall build-up, whilst letting moisture already inside the wall to escape.

It should be installed on the external side of the WikiHouse walls, between the chassis and the exterior cladding.

We recommend where possible using a low-emissivity breather membrane, often with a reflective surface, to maximise thermal performance.

The outside of your WikiHouse chassis is a flush and continuous surface so application of the breather membrane is typical and straightforward.

Roof waterproofing

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  • Building design and specification - Architectural designer
  • Product and system specification - contact a manufacturer for advice

Single ply membranes can work well for both the flat roof and pitched roof designed as they can be simply laid over the chassis.

A cold liquid applied membrane may also work well for roof terrace waterproofing, but it can be more expensive and messy to install.

Waterproofing layers must be installed correctly as per the manufacturer’s instructions. It is also worth checking that the roof finish you want will work with the waterproofing product you’ve chosen. Some finishes manufacturers may recommend you use their own waterproof membrane as part of their cladding system; this is often the case with green roofs and materials like standing seam.

The roof waterproofing layer needs to adequately lap over the breather membrane to ensure there is a continuous waterproofing layer.

Windows and doors

Skylark is compatible with pretty much any type of window or door. What's more, the precision and predictability of the chassis mean that the units can be ordered in advance instead of needing to be measured on-site, so your project doesn't need to be delayed for weeks while you wait for them to be made.

What type of windows?

Seriously, we mean it. You can use almost any type: fixed, sash, casement… timber, alumnium, alu-clad, uPVC. We believe that inward-opening, double-glazed tilt & turn composite windows look great and last well. Inward opening are easier to clean, allow for the use of shutters or shades, and give a strong sense of connection to the outside when open. Your door sizes and opening direction will need to align with regulations.

Double or triple glazed?

Modelling by Leeds Beckett University suggests that actually the extra cost of triple glazing (in money and carbon) won't really pay for itself over the lifetime of a WikiHouse. Good quality, durable double-glazed windows are probably where it's at.

Incidentally, it is an under-acknowledged rule that if you want to make a house feel robust and expensive, spend the money on the window seals and handles. The Germans seem to know this. Angela Merkel was once asked what, for her, defines Germany as a nation. She replied

“I think of airtight windows. No other country can build such nice and airtight windows.”


WikiHouse window and door blocks have standard opening sizes that should be accurate to within 2mm.

However, you may find that window and door manufacturers offer standard off-the-shelf sizes, and these may be considerably cheaper than having your windows custom-made. If this is the case, we recommend adapting the Skylark blocks to create smaller openings.

Seals and finishes

The most important thing is to make sure any gap between the unit and the opening is fully insulated, and fully protected from wind-driven rain using suitable flashings, tape, expanding seals or silicone sealant, and expanding insulation. It is impossible to overestimate the ability of cold wind or driven rain to find its way through even the tiniest gap around the edge of a window.

Make sure to design in a cill to the base of your window/door, and have it slope away from the building.


All the same applies to skylights (or 'rooflights'). There are a number of  companies who will make skylights that can be directly fixed onto the face of a WikiHouse chassis, making them surprisingly easy to install.

Openable skylights can be an important part of your strategy to keep the building cool in summer, by allowing hot air to escape upwards.

Get the frames delivered before you start

We recommend getting the windows and external doors ordered, delivered and waiting (safely) on site before you start assembling the chassis. Once the structure is up, the installers will want to get it wrapped and weathertight within hours, if possible.


A Skylark block showing a type of timber cladding attached to the block.

You can clad WikiHouse Skylark in anything you like. It is up to you to select your material palette, taking into consideration any planning or building regulation requirements. Non combustible materials may be required if your project is close to another building or boundary line.

The WikiHouse chassis offers a continuous 18mm layer to fix your cladding material or substrate into. The detail for this needs to be designed to suit your chosen cladding material.

Please do

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Use it

Most WikiHouse files and information are licensed under a Creative Commons–Sharealike licence, so you are free to use, distribute or modify them, including commercially.

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Check it

All WikiHouse information is shared 'as is', without warranties or guarantees of any kind. You are responsible for checking it and using it in a safe and responsible way, for example, getting it checked by a structural engineer.

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Comply with regulations

You are responsible for making sure your project complies with all relevant local regulations, including planning, building codes and health & safety legislation. If in doubt, seek professional advice.

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Re-share your improvements

If you make any improvements to the system, you must publish your files under the same type of open licence. However, you do not need to publish the plans and specifications for individual projects unless you wish to.

Please do not

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Call yourself WikiHouse

Do not call your company, organisation or any marketed product or service 'WikiHouse'. However, you may use the term WikiHouse to talk about the system, and you may describe your project, product, service or organisation as, for example, "using WikiHouse", "based on WikiHouse", "contributing to WikiHouse", or similar.

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Remove notices

Do not remove any licence notices from files if you are re-sharing them.

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Claim to be endorsed

Do not give the impression that you are endorsed by, or affiliated with WikiHouse or Open Systems Lab (unless you are, by written agreement), and do not claim to represent the WikiHouse project or community as a whole.