Pre-existing Dormer improvements

AmmDram

Asking for a friend… if there is a pre existing dormer loft conversion on a property (built decades ago so likely now non compliant with building regs) and in the interests of maintenance and repair someone wanted to replace the roof and cheeks of the dormer, adding more insulation to make it a more comfortable room to use… can they just go ahead and make the improvements to the outer section of the dormer, or will any improvements need to meet modern building regs? Thanks for any useful input here. 

FreeBear

If you are replacing more than 25% of a thermal element (i.e. flat roof, cladding, etc), then building regulations kick in. So stripping off the (presumably) flat roof and cheeks of the dormer would exceed the 25% rule and Building Control should be notified (but up to your friend if he/she/they go that route).

Regulations stipulate a minimum u-value for the roof & walls. Sometimes it is not technically feasible to reach the target, so one is required to do what is required to the best possible standard. Sometimes, other thermal improvements can be made elsewhere in the property to offset any shortcomings of the work in the dormer area.

AmmDram

Thank you for replying. If they find a roofing company to do the work, does the homeowner have to contact building control to come and have a look while the work is taking place? And would the regs just be relating to the thermal performance of the cheeks/new roof? Just concerned about a huge loft conversion rebuild can of worms being opened… 

AmmDram

FreeBear said:

If you are replacing more than 25% of a thermal element (i.e. flat roof, cladding, etc), then building regulations kick in. So stripping off the (presumably) flat roof and cheeks of the dormer would exceed the 25% rule and Building Control should be notified (but up to your friend if he/she/they go that route).

Regulations stipulate a minimum u-value for the roof & walls. Sometimes it is not technically feasible to reach the target, so one is required to do what is required to the best possible standard. Sometimes, other thermal improvements can be made elsewhere in the property to offset any shortcomings of the work in the dormer area.

They are also thinking of replacing a flat roof over the ground floor front porch with a proper tiled sloping roof and adding decent insulation, guessing this would need sign off from building control too? Thanks. 

Section62

AmmDram said:

Asking for a friend… if there is a pre existing dormer loft conversion on a property (built decades ago so likely now non compliant with building regs) and in the interests of maintenance and repair someone wanted to replace the roof and cheeks of the dormer, adding more insulation to make it a more comfortable room to use… can they just go ahead and make the improvements to the outer section of the dormer, or will any improvements need to meet modern building regs? Thanks for any useful input here. 

What you describe sounds more like an alteration than "maintenance and repair".

Important to appreciate the difference between the need to comply with the requirements of the Building Regulations when carrying out work, and the requirement to notify and/or seek approval.

The fact work doesn't need approval/notification doesn't mean you don't need to comply with the regulations - i.e. if you are only replacing 24% of the roof it doesn't mean you can do it defectively.

The Building Regs are effectively a minimum standard for safety, durability, and impact on occupants and the environment.  Anyone planning to do work on their own home to a lower standard than the regulations require should give their head a little bit of a wobble.

Also worth pointing out to your friend that surveyors are fairly good at estimating when work has been done - so when they come to sell they may have difficulties convincing people that the 'recently constructed dormers' have been there all along.

Section62

AmmDram said:

FreeBear said:

If you are replacing more than 25% of a thermal element (i.e. flat roof, cladding, etc), then building regulations kick in. So stripping off the (presumably) flat roof and cheeks of the dormer would exceed the 25% rule and Building Control should be notified (but up to your friend if he/she/they go that route).

Regulations stipulate a minimum u-value for the roof & walls. Sometimes it is not technically feasible to reach the target, so one is required to do what is required to the best possible standard. Sometimes, other thermal improvements can be made elsewhere in the property to offset any shortcomings of the work in the dormer area.

They are also thinking of replacing a flat roof over the ground floor front porch with a proper tiled sloping roof and adding decent insulation, guessing this would need sign off from building control too? Thanks. 

Clearly an alteration rather than 'maintenance'.  Possibly needing planning consent as well.

AmmDram

Section62 said:

AmmDram said:

Asking for a friend… if there is a pre existing dormer loft conversion on a property (built decades ago so likely now non compliant with building regs) and in the interests of maintenance and repair someone wanted to replace the roof and cheeks of the dormer, adding more insulation to make it a more comfortable room to use… can they just go ahead and make the improvements to the outer section of the dormer, or will any improvements need to meet modern building regs? Thanks for any useful input here. 

What you describe sounds more like an alteration than "maintenance and repair".

Important to appreciate the difference between the need to comply with the requirements of the Building Regulations when carrying out work, and the requirement to notify and/or seek approval.

The fact work doesn't need approval/notification doesn't mean you don't need to comply with the regulations - i.e. if you are only replacing 24% of the roof it doesn't mean you can do it defectively.

The Building Regs are effectively a minimum standard for safety, durability, and impact on occupants and the environment.  Anyone planning to do work on their own home to a lower standard than the regulations require should give their head a little bit of a wobble.

Also worth pointing out to your friend that surveyors are fairly good at estimating when work has been done - so when they come to sell they may have difficulties convincing people that the 'recently constructed dormers' have been there all along.

Thank you for your reply. This is not about trying to dodge doing things correctly, I was asking for advice so the correct channels can be followed as required. The roof is in a state of disrepair and as it is old and poorly insulated, it seems a good opportunity to improve it, rather than just nailing the edge of the felt down or bodging it. If the roof is being done, then may as well better insulate the cheeks too…? 

Maybe my choice of language on my first post has caused confusion. I meant does building control have to be informed and come to inspect it, not can we get away with any old bodge job! 

casper_gutman

Section62 said:

AmmDram said:

FreeBear said:

If you are replacing more than 25% of a thermal element (i.e. flat roof, cladding, etc), then building regulations kick in. So stripping off the (presumably) flat roof and cheeks of the dormer would exceed the 25% rule and Building Control should be notified (but up to your friend if he/she/they go that route).

Regulations stipulate a minimum u-value for the roof & walls. Sometimes it is not technically feasible to reach the target, so one is required to do what is required to the best possible standard. Sometimes, other thermal improvements can be made elsewhere in the property to offset any shortcomings of the work in the dormer area.

They are also thinking of replacing a flat roof over the ground floor front porch with a proper tiled sloping roof and adding decent insulation, guessing this would need sign off from building control too? Thanks. 

Clearly an alteration rather than 'maintenance'.  Possibly needing planning consent as well.

I suppose regs relating to thermal elements might not be relevant to the roof of a porch, if the porch is outside the thermal envelope of the house. But then if that were the case, why would you add insulation to the roof?

AmmDram

casper_gutman said:

Section62 said:

AmmDram said:

FreeBear said:

If you are replacing more than 25% of a thermal element (i.e. flat roof, cladding, etc), then building regulations kick in. So stripping off the (presumably) flat roof and cheeks of the dormer would exceed the 25% rule and Building Control should be notified (but up to your friend if he/she/they go that route).

Regulations stipulate a minimum u-value for the roof & walls. Sometimes it is not technically feasible to reach the target, so one is required to do what is required to the best possible standard. Sometimes, other thermal improvements can be made elsewhere in the property to offset any shortcomings of the work in the dormer area.

They are also thinking of replacing a flat roof over the ground floor front porch with a proper tiled sloping roof and adding decent insulation, guessing this would need sign off from building control too? Thanks. 

Clearly an alteration rather than 'maintenance'.  Possibly needing planning consent as well.

I suppose regs relating to thermal elements might not be relevant to the roof of a porch, if the porch is outside the thermal envelope of the house. But then if that were the case, why would you add insulation to the roof?

Sorry, porch may not be the appropriate word. It’s a small flat roof at the front of the house, but there is no internal door, it opens directly into the house from the main front door. I suppose it’s really a small extension but we think it may have been signed off as a porch, many years ago. It’s very cold in that area and the flat roof isn’t in a good state of repair, hence wanting to change it for a slightly sloping tiled roof. 

Just looking for advice so I thought I would ask on here as none of us have a clue where to start (as in, with tradesmen… do they sort all the info if planning/building control is required or is it on the home owner). And if it is on the home owner to speak to building control, at what stage because no local builders etc with good reviews seem to be available this year. 

Also, we have searched the internet for advice on both the dormer and changing the small flat roof and have so far drawn blanks. Thanks. 

FreeBear

Sounds like the porch area is part of the "habitable" space. In which case, the roof should be insulated. If you have single skin brick walls (100mm or so thick), then adding a good thick layer of insulation there will pay dividends.

As for your question "does building control have to be informed and come to inspect it" - Ideally, BC should be notified before any work commences and they will want to conduct periodic inspections. As the homeowner, you (or your friend) is responsible for contacting BC, not the builder/roofer/whoever is doing the work - Although, for some types of work, some tradesmen can self certify the work and do the Building Control notification (FENSA/CERTASS for doors/windows being one example).

AmmDram

FreeBear said:

Sounds like the porch area is part of the "habitable" space. In which case, the roof should be insulated. If you have single skin brick walls (100mm or so thick), then adding a good thick layer of insulation there will pay dividends.

As for your question "does building control have to be informed and come to inspect it" - Ideally, BC should be notified before any work commences and they will want to conduct periodic inspections. As the homeowner, you (or your friend) is responsible for contacting BC, not the builder/roofer/whoever is doing the work - Although, for some types of work, some tradesmen can self certify the work and do the Building Control notification (FENSA/CERTASS for doors/windows being one example).

Thank you, this is most helpful.