Here’s a photo just in case the attachment fails!

Hi there, thanks for your comments. I was trying to keep my first post as simple as possible but appreciate there’s far more involved.

I’ll be living here during the renovation, I’ve got a large garage, I’m sort of used to living primitively so we’ll see how it goes…

So far the builder has priced removing the kitchen wall, making the opening in the current patio doors bigger for some bi fold doors, installing it and the rest of the windows / doors. An electrician friend has offered to do the rewire with me providing the unskilled labour.

The stairs will be removed creating effectively a mostly insulated attic. I’ve been using a single mattress to block the stairwell up for a number of winters! There’ll be a pull down ladder with an insulated hatch for occasional access.

The upstairs perimeter (outside of the stud walls) has been mostly insulated with Rockwool. There’s a few bits missing due to access but I hope to sort those out when the ceilings / floor is done. The small stud walls could be insulated it’d mean me crawling around but I’d say it’s doable.

I’ll be getting new windows and doors all around. Budget dictates standard UPVC, I’m waiting on the specification but I’ve been told that I should be aiming for a U value of around 1.2 -1.4 (see below)

I’m not sure about trickle vents – there’s none currently but I appreciate I’ll need ventilation s I’ve has some mould and condensation issues on the windows in the winter. There’s currently just a rubbish extractor fan in the bathroom, nothing in the kitchen or elsewhere. There will be extraction fitted with external extraction in the kitchen and something in the bathroom. There’ll be a wood burner against the right wall of the lounge area. There’s also a wood burner in the room labelled lounge as I’ve been using it as such for 6 years it was installed before devising the renovation. It could possibly be removed but I’m sure it’ll be cost prohibitive.

I had a retrofit survey done by a nice bloke from Cardiff last year here’s what he concluded: The problem is mostly cost, availability of someone skilled enough to do the work. Almost no one I’ve met has heard of ducted demand controlled ventilation or MVHR etc.

The survey concluded:

Ventilation The property has no strategy in place. The bathroom is served by an extractor, but there is no extractor in the kitchen and nor do existing windows have trickle vents. Moisture build up is addressed by opening windows. Recommendations: • Install iMEV demand-controlled ventilation throughout the property via: • Relative Humidity (RH) controlled trickle vents specified in new habitable room windows • No trickle vents in wet rooms (bathroom and kitchen)

• Ensure an undercut on all doors of 10mm Centralised system to be housed in loft space and ducting to run from the outer sections of the ground floor rooms to ensure that all infrastructure lies around eaves rather than in the room in roof element. Additional extraction to be made via a new cooker hood (note recommendations for quiet version to enhance useability) Contact to AerEco installer: info@electricsfixed.com 3 ETH1984 EHT2

Quotations ranged varied but I get the impression that something fully installed would be around £4000 which is a large sum for me. I’ve got a drawing which I’ll try to attach if you think it’d be useful.

Unless I strike lucky and come across a contractor who’s in budget and knows what they’re doing then ultimately I’m seeking a fairly simple ventilation strategy that’ll deal with day to day moisture without sucking all the expensive heat out or opening the windows (my current strategy)

2. New windows and doors Existing double-glazed windows and doors are looking at little tired and require trickle vents. Current performance would be in the region of 2 – 2.4 U value. Recommendations: • New windows should be specified to be a U value of 1.2 – 1.4. • Trickle vents to be specified as above (note need for system approach e.g. aereco) • Check style, opening options to keep a uniform feel to the property. This may be important when looking at the rear and the options for changing the rear patio doors into a window. • Ask for new windows to be installed in a weather tight, air tight and insulating manner. This should be done in such a manner as to remove the thermal bridge around the reveals (note that this might involve removal of existing render and replacement with a wet insulating render. • Install windows with extended sills to facilitate possible external wall insulation.

The doors (to the right on the drawing) in the new kitchen diner will be made wider and some bi fold doors installed. These will be aluminium. I’m not entirely confident that my builder friend is up to speed as to the correct installation techniques to avoid thermal bridging and cold spots etc. Dialogue is proving difficult!

On paper this seems like a really simple renovation job but the more research I do more questions come to light than answers!

I’m super appreciative of everyone’s help and advice. Think I’m suffering paralysis by analysis, my Mrs is beginning to hate me!

Cheers

Huw

Evening and thanks for the warm welcome.

The existing wood burner doesn’t have an external supply although it can be retro fitted. As it'll be in the bedroom it probably won’t get used much, I’d like to uninstall it and move it to the kitchen but I don’t think it’ll be big enough for the larger room. If it can be removed inexpensively then I could sell it to off set the cost of the new one which will have an external air supply.

I’d imagine building control will be involved with the beam but not much else. I could ask their opinion on various other topics but I guess I wouldn’t want to unnecessarily draw their attention to other potential issues.

As the rooms upstairs are just makeshift do you think would have an issue with the loft ladder. Essentially it’d just be a loft and not a habitable space?

Thanks for the advice on the wool insulation it sounds much nicer to work with than rockwool or insulated boards. By foaming do you mean the perimeter? Do you think a vapour barrier would be necessary please?

The attic rooms are already insulated with the exception of the small stud walls. There’s 3 Velux windows up there too which I tend to leave open slightly. It’s not really possible to insulate the attic floor although it does have a carpet though. Insulating from above would make the space unusable due to the ceiling height. There’s a couple of small radiators up there as well so it’s not necessarily cold in the winter and the windows would keep it from getting too hot in all but the hottest weather.

I’ve just had a look at demand controlled positive input ventilation. I’d understood these to be responsible for pushing already warm air out through the fabric of the building this potentially wasting energy. Perhaps I’m wrong do you have a link to the system please? Assume that would require trickle vents, undercut doors etc as described in the survey I had done?

I tend to agree with you in respect of builders. Someone who genuinely has an interest in any kind of systematic approach to sorting ventilation or condensation are in very short supply. Any suggestions in South Wales greatly appreciated!

This is a big financial deal to me so getting in right or as close to right as possible would be amazing.

Thanks again for the responses. Any further pearls of wisdom gratefully accepted.

Posted By: djhWhen Peter said 'wool type insulation' I think he was meaning anything flexible and fluffy, so including rockwool and glass wool as well as sheeps wool. Glass wool is awful, but rockwool isn't too bad as long as you cover yourself up well. You can also buy recycled plastic bottle wool I think, which is very pleasant to handle but expensive.

Yes I meant glass wool or rockwool. Sheeps wool also works but is expensive and IMO not worth the premium. By foaming I mean squirty foam around the perimeters.

Wood burning stoves without external air supply in a reasonably air tight house create at best a stuffy atmosphere and at worst a deadly one (Locally a few years back a family fitted nice new plastic doors and windows, did nothing about the wood burner and 3 of the 4 died over night !!)

Over here if you have to buy in ready cut fire wood then it is as expensive as heating with gas. If you have the time and equipment to buy in logs and process them or have your own source of wood then wood is cheaper. I don't know the economics of where you are, or do you want the stoves for the aesthetic look/feel?

If you have 3 velux windows in the attic rooms then BC are likely to view them as habitable and apply the regs accordingly.

Yeah I know the boiler is a whopper it was accidentally over specified for the same cost. It’s a little place and really doesn’t need wood burning stoves but I’ve got access to some free wood as long as I process it myself. Also it’s been so grim here over winter that it’s made a real difference to morale!

In terms of ventilation it’s looking like trickle vents, should they be fitted to all the windows? Decent extraction in the kitchen and bathroom. Like you said I’ll just have to suck up some extra cost in heating loss. Can anyone recommend a quality bathroom extractor please? Humidity controlled I would imagine?

I wonder if I get a secondary kitchen extractor to deal with background moisture? Perhaps I’m thinking a bit too hard (again)

As for the insulated ceiling / flooring I’ll get something fluffy that doest’t itch too much, Rockwool sounds good.

Does anyone have an opinion on a vapour barrier please? Builder doesn’t seem to think it’s necessary as the room above are insulated from above. In theory the small radiators up there could be left on very low as sometimes I dry clothes up there albeit with the velux windows slightly ajar.

I’m going to contact building control for their view on the stairs and the habitability of the rooms upstairs before I remove them.

Thank again everyone. I’m very grateful for your wisdom?

Posted By: Huwblutand most of the ceilings are cracked so they’ll be coming down.

Assuming the ceilings are plasterboard I wonder why they are cracked. If it is the joints it sounds like the joints were not properly done. Providing you don't have Artex or similar it would be cheaper and less messy to repair the cracks with 2" wide glass tape (made for the purpose) over the cracks with finishing plaster feathered in to the existing ceiling.

https://www.powerdiscount.co.uk/greenwood-unity-cv2gip-smart-versatile-100mm-extractor-fan-764-p.asp?gad_source=1&gclid=Cj0KCQiAm4WsBhCiARIsAEJIEzW-EMRlfE57Q_GDF8VzwIRhnFiQhzTplwUr-qBiU5MOeAwWkVEJM0YaAgTgEALw_wcB

Slightly confused about what had been specified for you before. I don't think 'iMEV demand-controlled ventilation' (as per your survey) is MVHR. AFAIK there is no HR in what was suggested to you, and there isn't in dMEV, but there's a big cost difference. I would expect a very basic solution to be a lot less brilliant than a well-spec'd expensive one, but hey, think how you can spend the difference.

Posted By: HuwblutAs the rooms upstairs are just makeshift do you think would have an issue with the loft ladder. Essentially it’d just be a loft and not a habitable space?

Irrespective of their Building Regulations status, using a loft 'unofficially' as a room is a fire risk - I wouldn't want to any of my relatives or friends to use it.

Posted By: Peter_in_HungaryWood burning stoves without external air supply in a reasonably air tight house create at best a stuffy atmosphere and at worst a deadly one.

Yes, it's dangerous. Take it out (best solution) or provide a dedicated air supply that complies with the Building Regulations.

Posted By: HuwblutCan anyone recommend a quality bathroom extractor please? Humidity controlled I would imagine?

For a fan only, then Airflow Icon Eco.

Posted By: HuwblutIn terms of ventilation it’s looking like trickle vents, should they be fitted to all the windows?

Yes, if you're using extractor fans.

Posted By: HuwblutDoes anyone have an opinion on a vapour barrier please? Builder doesn’t seem to think it’s necessary as the room above are insulated from above.

Vapour barriers between floors aren't useful - indeed vapour barriers anywhere may cause harm rather than help.

What's most important is that the outside perimeter of the house should be made as airtight as possible (an air barrier, not a vapour barrier), other than deliberate penetrations for air supply & extraction. This may involve the use of a vapour control membrane - different from a vapour barrier as it allows moisture vapour to pass through it (it's 'breathable').

Posted By: Huwblut£60 is considerably less spendy than the MVHR quote. As to why it was prescribed I really don’t know.

As Nick mentions, iMEV is not the same as MVHR. MVHR is the gold standard, significantly more expensive, but a good one can recover most of the heat and so reduce your heating bill, provided the building has been made relatively airtight. There are also other benefits, including maintaining healthy internal air quality and avoiding the need for trickle vents. If you're taking ceilings down, now is the time to be considering it. If you're not ready for the expense, you could still install ducts for a future installation, as djh mentions above.