Where do I start - solar or heat pump?

MallyGirl

Exiled_Tyke said:

Octopus told me that they won't install an ASHP unless there is 300mm of roof insulation. (That's what I meant by 'well insulated')   It's worth checking how much is up there as the suggested depth seems to have gone up over recent years.  

The roof has a vaulted ceiling room built in so there would be no economic way of improving the insulation if it is insufficient. It is celotex type panels from what I can see but won't be 300mm. I am going to follow the PV path and look at secondary glazing for now. Anything else would be significant disruption or would damage the period features which were a reason for buying the house. It's all a balance.

Reed_Richards

The 300 mm figure assumes you have a loft with a 300 mm depth of loft insulation.  It will not apply to a pitched roof with insulation between the rafters under the tiles.  I don't know how Octopus would view this but the constraint on getting the £7.5k grant is that your EPC must not recommend further loft or cavity wall insulation.

MallyGirl

Thanks. I suspect that a heat pump is a non-starter

paul991

After you have done the insulation work have a EPC done and see what is recommended

Waywardmike

MallyGirl said:

Thanks all. 

We have loft insulation but the walls have no cavities to fill. The internals are quite twiddly- picture rails, ornate skirting, lots of coving, fireplaces, bookcases built into every alcove - so insulating inside would be difficult and destructive. We will need to strike a balance there. We did put in the best underlay we could get when we carpeted a room with just floorboards previously. 

You have the issue as me.  I love the high ceilings but it does annoy me knowing all that warm air is up there several feet above my head.  We ended up putting internal insulation on the worst room (north facing), which regularly suffered from condensation on the walls and it was transformative.  We did lose about 4" on the two external walls doing this and although it doesn't seem like much it was significant.  I'd love to insulate the external walls but sadly budget doesn't stretch that far. 

We have air/air heat pumps and I have one on overnight during the cheap electricity period which makes a huge difference, the other turns the bedrooms' into a sauna so I don't put that one on while we're sleeping.  We also have solar, and as the sun is blazing today, the battery is filled ready for when the sun sets, it's heated our hot water and the heat pumps are on, all for free.

Meatballs

MallyGirl said:

Exiled_Tyke said:

Octopus told me that they won't install an ASHP unless there is 300mm of roof insulation. (That's what I meant by 'well insulated')   It's worth checking how much is up there as the suggested depth seems to have gone up over recent years.  

The roof has a vaulted ceiling room built in so there would be no economic way of improving the insulation if it is insufficient. It is celotex type panels from what I can see but won't be 300mm. I am going to follow the PV path and look at secondary glazing for now. Anything else would be significant disruption or would damage the period features which were a reason for buying the house. It's all a balance.

You won't need 300mm if it is Celotex - as it is a higher performing insulator. The 300mm rule of thumb is for rockwool/fibreglass loose insulation. 150mm should be equivalent but it all depends on what your EPC says. You may need to have another EPC done and speak specifically to the assessor about it beforehand because they will either say they cant put anything down as they have no evidence or will say 'assumed' if you provide some documentation or something. 

If you have 100mm celotex you may not get a recommendation for more loft insulation. 

A ceiling fan is generally low energy and could improve comfort allowing you to drop the temp a bit and therefore save energy overall. 

Screwdriva

Meatballs said:

A ceiling fan is generally low energy and could improve comfort allowing you to drop the temp a bit and therefore save energy overall. 

Especially a DC Ceiling fan. Fantasia is a known seller of these. 35W or less peak draw. 

I'd recommend getting an EPC done after you install Solar as these will add points to your overall rating while still providing the insulation recommendations. 

paul991

check for grants on your energy suppliers and local councils website a friend of mine managed to get solar pv for free and some money for insulation

ispookie666

This is what I would do 
1. Air con - aka A2A heat pump - along with Planning permission
2. Solar PV - including ground mounted 
3. Battery 
4. Insulation 
5. ASHP 
You are highly unlikely to break even with GSHP 

RAS

MallyGirl said:

We will need to strike a balance there. We did put in the best underlay we could get when we carpeted a room with just floorboards previously. Hall and upstairs are all still floorboards or tiles. 

What is under the floorboards? Any idea?