Frequently Asked Questions
Here are some frequently asked questions we’ve received and we thought the answers might be helpful for everyone.
There is a very technical answer to this question but rather than give you the more scientific response, we will give you the meaning of the term in relation to traditional timber frame construction. Green means freshly sawn timber that has a high moisture content and is used before it starts to dry out too much.
There are several advantages to using green oak:
1) Green oak is cheaper than oak that has been dried (seasoned oak)
2) Green oak is more readily available than seasoned oak
3) Green oak is easier to cut so easier to work and kinder to our tools
It depends on how the timber will be used. We source all our wood from responsibly managed UK woodlands (FSC-certified), as close to us as possible. This includes our Larch and Western Red Cedar cladding, as well as some English Oak for characterful features like curved timbers in our Cruck frames. For projects that require straight, knot-free timber — such as glazed extensions — we use French-grown Oak (PEFC-certified). Oak naturally shrinks as it dries and tends to distort more around knots, which isn’t ideal when working alongside glass. That’s why we carefully select the most appropriate timber for each job, and the managed forests in France are our closest reliable source for this specific grade of Oak.
We provide a fixed quote and ask for 40% of the total as a deposit before construction work starts so we can buy the timber. The Second payment of 50% is due before we arrive at your site on the agreed date. The final payment (10%) is due once the frame has been installed.
Whether Planning Permission is required depends on several factors, including the size of the footprint, eaves and ridge height, proximity to boundaries, its position on the property, and the location of the property itself — for example, if it lies within a conservation area, Area of Outstanding Natural Beauty (AONB), Site of Special Scientific Interest (SSSI), or National Park.
We are aware of the planning guidance on extensions, outbuildings and porches but we are not Town Planners so we always ask you to check with your Local Authority first. The Government have produced useful guides on the Planning Portal website that offers good information. (The link here opens up in a new window ‘Planning Portal’).
If the property is listed, any structure built within its grounds — even something as minor as a rose arch — will require Planning Permission. However, Listed Building Consent is only required if the new structure physically touches or is attached to the listed building itself.
Green Oak Glazing
We design our green oak frames to be compatible with face or direct glazing. This specialist glazing method does more than simply hold the glass in place — it encapsulates the entire frame to protect it from the elements and movement over time.
In simple terms, a specialist oak frame glazier applies the glazing on the outside face of our green oak frame with a coverboard ‘clamping’ it in position.
- The glass units are cushioned using specialist glazing tapes to allow for the natural shrinkage and movement of green oak.
- Dry oak cover boards, the same width as the structural oak behind them, are fitted over the joints to conceal and protect the glazing.
- Additional elements like copper linings and drainage channels are incorporated to manage water and ensure long-term performance.
This method not only protects the glass from stress and cracking but also seals the frame, reducing heat loss and preventing water or air ingress.
Face or direct glazing is widely used by quality framing companies because it:
- Complements the aesthetic of traditional oak framing
- Protects the structural frame and the glazing system from movement-related damage
- Increases the longevity of the internal frame by keeping it dry
- Requires very little maintenance over time and if the cover boards ever need replacing in the long term, it’s a straightforward process — unlike repairing the structural frame itself.
Because the dry oak cover boards are made to match the width of the green oak timbers, the frame looks consistent from both inside and outside. All of our glazed extensions use this glazing system — you can view examples in our Gallery.
Glazing green oak frames is a specialist process, so costs vary depending on the project.
As a general guide, for a moderately sized extension, you can expect to pay around one and a half to two times the cost of the green oak frame, depending on the:
- Size and number of glazed areas
- Type of glazing (double or triple)
- Style and number of doors
- Visit Homebuilding & Renovating’s website for a helpful article on direct glazing.
- Or check out Topworks Bespoke Joinery, the specialist oak frame glazier we work with — you may even spot some of our projects featured there.