Oakwrights Architectural Designer, Pete Tonks, joined Homebuilding and Renovating for a live Facebook Q&A. You posted your questions on designing and oak frame homes and here are his answers -
Q. My wife and I are planning to build a ‘lifetime home’ (nice way of saying something with no steps for our knees) and so a bungalow seems like the obvious choice. Have you got any tips on layout to make the most of the space if we are sticking to one storey? And what nice design features could we include to make it look less like a traditional bungalow?
A. I could take you on a completely different design journey for a single-storey dwelling which would be quite different perhaps from your perception of a bungalow. It's all about the flow and transition between zones and spaces. We would avoid corridors completely and look to get lines of sight through the various spaces and out to the garden — it's about space and connectivity. You could consider a barn, coach house, or stables design direction and use different roof heights to break things up a bit.
Q. We want to put a significant extension onto an old cottage. Two questions: (a) is an oak frame appropriate in this scenario? and (b) can an oak framed building achieve insulation and air tightness at the same levels as a SIP constructed build (which is the other option we are looking at)?
A. We can definitely do oak frame extensions. Air tightness and insulation are optimum with oak frame as we externally wrap the frame with insulated panels.
Q. With regards to wrapping the frame, how do you achieve the look of the exposed frames externally (as per the image above) are there two sets of oak frames?
A. Yes, exactly that! Historically, the open frames that we all know and love would have been infilled as small panels into each of the frame apertures. As building regulations have progressed so has the technology behind oak framing where air tightness is key.
If a client wants a framed facade then this is achieved with the main structure being fully integral and in effect a half-width frame within the encapsulation buildup. Elements of the elevations such as bargeboards, fascias, soffits and rafter feet etc., are also fitted after the encapsulation to avoid the structure puncturing through the encapsulation panel system.
Q. I’m building a rear kitchen extension. Tiled, pitched roof with 8x2 roof joists what size/type of insulation should I use? How much air flow do I need?
A. If your roof is vaulted which I guess it might be then with an 8x2 rafter you can either decide to insulate within the structure or above the structure. If you insulate between the rafters you could use 6" and then overboard inside with a 1" board and then your plasterboard. If you do a warm roof (i.e. outside of structure) then you can go as thick as you want but keep an eye on visual build up. Generally airflow gaps should be 50mm to meet building regulations.
Q. With an exposed timber frame and vaulted ceiling, what are the best ways to incorporate lighting? I can see how spotlights could be easily installed, but I really want a big pendant and can’t see any other way to wire it than to run wires along the beam on the internal ridge.
A. Lighting an exposed oak frame with vaulted ceiling can be really cool. You should consider LED strips around the top of the frame before the roof slopes in at wall plate level. These are much more available nowadays and sensibly priced. If you know where you want the pendant you can get the hole drilled and first fix wiring in place before the roof gets tiled. That way, the cable can just drop straight through.
Q. Obviously timber is quick to burn, what concerns about fire safety should there be when building an oak framed home?
A. Structural timber is in fact not quick to burn. Research shows that firefighters would rather enter a timber frame building on fire as timber has a known and predictable burn and char rate and is not explosive. All timber frames commercially available have to be manufactured and erected in accordance with all regulations and warranties. Lenders and insurance companies do not differentiate between timber frame and masonry construction.
Q. We’re building a house in north Wales. We want three oak arch brace trusses in the living room (upper floor with the bedrooms on the ground floor). We’ve been told that such trusses aren’t feasible owing to the size of the span (10 metres although each timber will be no longer than approx. 8 metres). Is this right, or are these trusses a viable option?
A. 10 metres is a big span if it’s a clear span? You could perhaps subdivide that span into a main central frame of 5 metres with a 2.5m aisle each side. This would work if you were happy to have some posts within the building. The pitch of the roof at 10m span this could otherwise end up being very high.
Q. Do you think an oak frame home would be feasible for a first-time self-builder? I love the look but think it may be out of my budget.
A. Oak frame is feasible for anyone and as always, we design a house that we know can be built for the client’s budget. This sometimes involves advice from my side as to perhaps making the house smaller so as to allow the inclusion of an oak frame.
Oak frame is such an amazing thing to live with that I do find my clients are happy to accommodate design changes if it means they can have it. We are also experiencing that an oak framed house when finished is realising resale costs of around 20% more than average market value.
Q. Communities minister Eric Pickles has said that local councils should not see small developments such as self builds as cash cows when considering planning applications. Nevertheless this is happening and expensive evidence production and checking is being demanded by Councils looking for an Affordable Housing Contribution from granting planning permission. How can self-builders protect themselves from these costs and levies?
A. Self builders are fair game as ever as local authorities assume we all have pots of money and want to build lavish expensive homes. Custom build/self build is obviously on the verge of becoming more attainable for more people and our experience has been a 100% increase in business in the last 12 months so of course things are under the microscope.
As a private self builder you are exempt from Community Infrastructure Levy (CIL) which can be dealt with using the relevant forms when applying for planning. Exemption is subject to certain criteria and it is advisable to check with your planning authority. I don't see why a private self-build should be linked to providing affordable housing contributions elsewhere.
Q. We have a two/three bed bungalow that needs complete refurbishment and would also like to extend up (loft conversion), but the foundations and the height of the roof are not sufficient. We would also like to extend out to the front to make the most of a great view. We have no garage and also would like a kitchen ext. How does a budget of 100,000 to 125,000 sound and who is the best person to get to help design and budget cost for what we can afford? It's silly doing a design and getting planning before costings. We have never done this before. We both love oak and glass and live rural in a small village.
A. With your budget, it is unrealistic to consider a replacement dwelling and therefore extend/remodel is your only option. I would sit down with you to discuss the exact requirements and we would then do a design/cost analysis to see where we can most effectively concentrate our design efforts versus budget. We are shortly going to be undertaking our third extension and across all three, I guess we would have spent a similar amount to your budget. But we have doubled the size of the house, and we really love it!
A good designer/architect would be able to do a feasibility to get you comfortable prior to going through the planning application process.