Hi Guys, hope you can help. Looking at having a small extension built on back of house off the kitchen as a breakfast area. I understand that the maximum area of glazing I can have is 25% of extension floor area plus area of window taken out. Is there any way of increasing glazed area for same size extension ?
Glazed area
- Thread starter cosmosman
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Yes there is, provided that you can increase the thermal resistance elsewhere, i.e. by beefing up the floor, walls or roof insulation.
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There are 2 other methods of showing compliance. You can do a simple calculation whereby the you may be able to show that you've 'traded off' the heat loss from the extra glazing with better-than-minimum insulation elsewhere (see paragraph 18, Approved Document L1B). This may require you to beef up the insulation somewhere, as noseall said.
Alternatively, you could hire a SAP assessor to do a report of your proposal (see paragraph 20, Approved Document L1B. This will take into account more factors than the first option (energy efficiency of boilers, orientation, shading factors etc) so is arguably a less 'clumsy' tool than the first and may save you having to provide that extra insulation.
As I normally say to clients, nothing is impossible if you're willing to pay for it.
New rules are due to come into play in October though, which pose an additional 20-25% tightening of heat-loss standards.
Alternatively, you could hire a SAP assessor to do a report of your proposal (see paragraph 20, Approved Document L1B. This will take into account more factors than the first option (energy efficiency of boilers, orientation, shading factors etc) so is arguably a less 'clumsy' tool than the first and may save you having to provide that extra insulation.
As I normally say to clients, nothing is impossible if you're willing to pay for it.
New rules are due to come into play in October though, which pose an additional 20-25% tightening of heat-loss standards.
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Compliance with L1B for overglazed structures can be a complex issue. I find that the SAP assessment route nearly always works best because it is the only method that takes into account the solar heating due to the greenhouse effect. Expert advice will ensure a cost effective solution allowing lots of glass to be incorporated into the design.
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Tophouse
Firstly welcome, however please look at the date of the thread when you do a search, especially if the information you are adding is just routine.
Firstly welcome, however please look at the date of the thread when you do a search, especially if the information you are adding is just routine.
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Tophouse
Firstly welcome, however please look at the date of the thread when you do a search, especially if the information you are adding is just routine.
Firstly welcome, however please look at the date of the thread when you do a search, especially if the information you are adding is just routine.
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