So many choices.. PV, SA, UVC, MVHR...

[Adam2]

Well, my default option of a gas boiler and TS + UFH is probably going to change :-).... so much reading done, so much more to do I suspect.

 

Here's my scenario:

~320m 4 floor house with 4 beds, 4 bathrooms, 3 adults + guests (& dog and cat)

House is yet to be built (current house is similar footprint but remodel is not wanted) planning on ICF, hollow core for ground floor, possibly timber for 1st floor (to reduce weight) - this floor will be wood finish not tiled) foundations/slab a bit complex as house is stepped down a hill so effectively has 3 ground levels - see crude attached image. Terraces above the blue box and green box floors

 

I appreciate there is a lot of glazing so need a strategy to handle solar gain. Am thinking here a combination of brisse soleil, appropriate glass, possibly interior blinds

UFH is planned to all floors - appreciate top floor may not need this but incremental cost is low

No need for gas as happy with elec hob but house currently has gas if needed

 

Thinking of

- ASHP for UFH

- DHW I was thinking Roof mounted PV excess going to a "store" of some sort SunAmp, UVC that would be "charged" by PV and mains as needed, was planning on gas boiler but now not sure that is needed if it won't get used very much would save on purchase at cost of some higher electricity.

 

DWH capacity - very unlikely we would use more than 2 showers at the same time

 

Like the simplicity of using ASHP just for UFH + the cooling benefits I read about here ?

 

Also will have MVHR to assist with heat re-circulation/minor cooling effect (I believe it is minor)

 

Planning a 1m roof light on top floor above stairs to help with heat loss in summer and given S coast location expecting often to have some through house wind ventilation if needed

 

It's a complex project start to finish ? Foundations, retaining walls etc etc but will be worth it.

 

I'd appreciate suggestions if I've missed any sensible options re heating/DHW. I like simplicity not hung up on no gas but if the ASP + PV + SunAmp/other store works as efficiently (within a few %) then am happy to skip that.

 

Have not got around to looking at sizing of PV setup/ASHP/SunAmp etc that I guess is next. I'm not interested in FIT/RHI based on what I've been reading re cost differentials so need something that can be installed by a competent electrician/plumber.

 

Thanks

Adam

 

 

 

 

 

Edited October 16, 2018 by Adam2

[lizzie]

however you power it I highly recommed MVHR & UFH + heated towel rads.  V cosy warm house,

[Adam2]

Managed to grab an image from the animation that may make this clearer to grasp (from a solar gain perspective). Some changes since this was created.

 

[Alexphd1]

Very nice design. With that amount of glazing, maybe worth considering a full ducted AC system? 

MVHR is a no brainer. 

Mains gas system boiler,  sunamp. Wether you run a buffer tank Nick is your expert who actually knows his stuff! 

What ICF have you been looking at?

 

[Adam2]

11 hours ago, Alexphd1 said:

Very nice design. With that amount of glazing, maybe worth considering a full ducted AC system? 

MVHR is a no brainer. 

Mains gas system boiler,  sunamp. Wether you run a buffer tank Nick is your expert who actually knows his stuff! 

What ICF have you been looking at?

 

Thanks, we're very pleased with the design but the vision is a long way away still....

ICF - talking with 3 Nudura, Logix (local to me) and Amvic.

 

[Big Neil]

1 hour ago, Adam2 said:

What ICF have you been looking at?

 

Maybe consider Polarwall (assuming you haven't already discounted it), as Alan there is incredibly knowledgeable and extremely helpful. I believe Vijay on here is using that system.

[lizzie]

What are you doing to mitigate solar gain and overheating on all the glazing?

[jack]

14 minutes ago, lizzie said:

What are you doing to mitigate solar gain and overheating on all the glazing?

 

14 hours ago, Adam2 said:

I appreciate there is a lot of glazing so need a strategy to handle solar gain. Am thinking here a combination of brisse soleil, appropriate glass, possibly interior blinds

UFH is planned to all floors - appreciate top floor may not need this but incremental cost is low

 

That said, I think you're right to underline this @lizzie. That's a LOT of glass.

 

@Adam2, what direction is this heavily glazed elevation facing? Anything other than north and I don't think it can be overemphasised how important solar gain control will be.

 

Be aware that while internal blinds will help, they're hugely less effective than stopping the sunlight before it reaches the windows. We have external blinds on some windows and they do a great job of cutting solar gain down to almost nothing. In the one room (east facing main bedroom) where we should have had external blinds but chose not to install them to save money, blockout fabric curtains still leak an awful lot of heat in the mornings.

[Alexphd1]

Big fan of ICF esp nudara (used on parents build), also impressed with amvic (hands on with a neighbours) . I plan on using nudara but will go with the best  price.

 

I can see icf build being good for your 1st two floors but top two maybe better looking at something lighter as very few walls (internal and external) which match up with walls in the floor below. It. It can be done with icf but a lot of steel work.

 

[Adam2]

16 minutes ago, lizzie said:

What are you doing to mitigate solar gain and overheating on all the glazing?

Hi, yes exactly - it is a design consideration ? 

 

Glazing does face south. The existing house has ~75% of the planned amount of glazing in this aspect compared to the new one, will ask my friend that is staying there how he has coped during the summer! Current glazing is pretty old

 

Natural shading/buildings providing shading:

Basement level = very high cover so not concerned here

LG level = partial shading from East  through to S

GF = somewhat less shading than LG

1F= not much shading

 

For LG & GF we may need glazing that stops solar gain at the expense of losing some of the benefits in winter + the use of external measures - brisse soleil and possibly external blinds - any links and info on those appreciated.

 

for 1st floor probably maximum solar reduction in glazing as we will not need the solar gain in the summer. Louvres in design for upper window and may consider roof projection a bit further but this is limited help as slopes upwards but in peak season may be beneficial.

 

Have been looking at split single room A/C units and possibly we should incorporate wiring/conduit for these should we feel they would be beneficial in future. Not sure if there are add-ons to MVHR that could improve cooling ability if needed later. 

 

Having UFH with single floor zoning may be benefical in evening temp from S and N areas of the house? 

 

Thanks

Adam

[Nickfromwales]

Solar PV would be 'interesting' with that shape of structure.  

All electric would be a neat solution, but its down to heat loss figures and matching the solution with the problem. Best to do a proper analysis on overheating as cooling ( with that huge amount of glass ) could be more of a consideration than heating ! The biggest issues will be on the upper two floors, so be 100% diligent in your investigations. 

Too early to have a stab at whats going to be best TBH, but I think you'll do well not to have to have active cooling on the upper floors, annoyingly just to deal with the peak months for solar gain. This could be mitigated largely with a good solar reflective coating / film as some have done with good results, and I think I'd start there. I don't think it would harm to run this through PHPP even if your not going that route, just to get a well defined breakdown of risks and requirements.

A SA for DHW is a no-brainer, just to get away from G3 and discharge pipework more than anything, but with a heat sensitive house you also want too actively reduce standing losses from any such device. An ASHP is likely, as you'll need a fair bit of heat in the winter, but you'll also have a means to provide active 'cooling'. You could also go for wet duct heaters / coolers in the upper floors to accent the ambient eg do away with UFH for the very upper floor at least. Wet duct heaters for the gym may be attractive too, so you could run cooling just there whilst doing some thing called exercise. I'll google that later, maybe     

Edited October 16, 2018 by Nickfromwales
crossed with the previous post

[Nickfromwales]

5 minutes ago, Adam2 said:

Have been looking at split single room A/C units and possibly we should incorporate wiring/conduit for these should we feel they would be beneficial in future. Not sure if there are add-ons to MVHR that could improve cooling ability if needed later. 

The wet duct heaters recirculate in the rooms, and stand alone from the MVHR. They should be less intrusive, require no external wall warts, are nearly zero maintenance other than cleaning, and would run off the ASHP.

[Adam2]

13 minutes ago, Alexphd1 said:

Big fan of ICF esp nudara (used on parents build), also impressed with amvic (hands on with a neighbours) . I plan on using nudara but will go with the best  price.

 

I can see icf build being good for your 1st two floors but top two maybe better looking at something lighter as very few walls (internal and external) which match up with walls in the floor below. It. It can be done with icf but a lot of steel work.

 

Good to hear. We met with a local who is doing a Nudura build (just finished concrete pour on top floor) who is also enthusiastic.

Our architect and their often used (hesitant to say preferred) SE firm are pretty negative about ICF through lack of experience - for example their response back to the architect is below - nothing is probably actually 100% wrong (though I don't recognise some of the issues/terms used!) but indicates their view. Needless to say, I'm talking with other SEs that have ICF experience.

1. The main concern on this project would be the waterproofing system.  With an ICF product, how would the product be guaranteed?  Typically the crack widths would need to be no bigger than 0.2mm.  These are controlled by the amount of reinforcement and the cover to the reinforcement.  With ICF both the amount of rebar that can be incorporated with the wall and the cover tend to be fixed or difficult to change.  How would the walls be checked to make sure that 0.2mm crack widths have not been exceeded.
2. The house has a lot of large openings.  These could be difficult to prove using ICF due to the fixed width of wall.  There are only so many bars that can be placed within a certain width of wall.  This could mean that steel beams and or columns are required, causing further issues with detailing around the interfaces between the two.
3. Care needs to be taken when installing kitchen and bathroom units as the fixings need to be taken through the polystyrene and into the concrete.  The insulation could compress causing the units to be un level and out of alignment.
4. Detailing of structural elements can prove difficult trying to comply with the detailing code. 
5. The system is advertised as low level skill required to construct the system but in reality tying of rebar and pouring of concrete are skilled jobs and need skilled labour to carry them out.

 

 

[the_r_sole]

.

Edited September 26, 2019 by the_r_sole

[lizzie]

@Adam2 I think I would go for solar glass if I were you, much cleaner.....  I have a major overheating problem on south/west elevations and I am single storey.  I have investigated lots of external blinds (can give you company names but not recommends as not used the product) and may yet get a couple fitted next year but for me that is now a challenge as building is complete and cabling is a problem.  I think @vivienz is having external blinds and bris Soleil..

 

I am having external solar film fitted this week on my living area windows (S&W), I have had a long journey to find a film suitable for my laminated windows..... I have internal black out  blinds in the bedrooms and I they are not very effective for solar gain.  I am told you need to stop the heat getting in, once its in and internal blind will just help keep it in.

[epsilonGreedy]

I feel the fine tuning of such an inspirational modern design should be left to a high-end professional after you have gathered opinion here.

 

Is this some multi £ million pad to be built in Sandbanks Poole? Those pine trees look familiar.

[Adam2]

Thanks, such helpful responses. @lizzie yes I was reading your challenges there on the film. 

 

@the_r_sole that could be a sensible approach ? there may be some economy there as well - for example bringing the wall up to the roof line and in slightly more on the left. The views are quite amazing though so we need to ensure we get the balance right (for us) regarding glazing/views/heat etc.

 

Thanks @Nickfromwales will look into that - it is new to me. As the real issues are (usually) confined to 1-2 months of the year I was thinking AC prep would be a bit of risk mitigation for bedrooms.

 

It's great to have suggestions to make us review (again) the design, after all - this is the cheapest time to do it!

 

I'll have to study a bit more the effectiveness of different glass treatments to see how they can help with the top floor as there we are unlikely to need any solar gain in the winter.

 

 

[Nickfromwales]

2 minutes ago, Adam2 said:

Thanks @Nickfromwales will look into that - it is new to me. As the real issues are (usually) confined to 1-2 months of the year I was thinking AC prep would be a bit of risk mitigation for bedrooms.

Agree, but the A/C will be split units = ugly and noisy ( IMO ) . Wet duct heaters can be integrated behind / above fitted wardrobes and have near zero visual impact . 

[Adam2]

14 minutes ago, epsilonGreedy said:

I feel the fine tuning of such an inspirational modern design should be left to a high-end professional after you have gathered opinion here.

 

Is this some multi £ million pad to be built in Sandbanks Poole? Those pine trees look familiar.

It won't be multi-millions else I'm in trouble ?

Good guess re location - not in Sandbanks, much cheaper than there but nice views as we're on top of a hill and get some views over Poole harbour

[epsilonGreedy]

19 minutes ago, Adam2 said:

Good guess re location - not in Sandbanks, much cheaper than there but nice views as we're on top of a hill and get some views over Poole harbour

 

 

Nice and a great design for the location.

 

Having sailed in and out of Poole many times I have been able to eyeball the development of Sandbanks from seaward and can imagine the lifestyle such a property will offer.

[NSS]

Google SageGlass. It works for us.

[Nickfromwales]

1 hour ago, NSS said:

Google SageGlass. It works for us.

Just remove all sharp objects from the house first  

 

[Adam2]

2 hours ago, NSS said:

Google SageGlass. It works for us.

Yes- I had seen the posts mentioning that. When I feel ready for a laughing session I'll ask for a quote for the bedroom and ground floor (where the TV will be)! I think we're a few years too early for this product to drop in price but would love to know some indicative costs for this - I think @NSS you were an early customer so had a good deal? 

[NSS]

8 minutes ago, Adam2 said:

Yes- I had seen the posts mentioning that. When I feel ready for a laughing session I'll ask for a quote for the bedroom and ground floor (where the TV will be)! I think we're a few years too early for this product to drop in price but would love to know some indicative costs for this - I think @NSS you were an early customer so had a good deal? 

We were I believe the first UK residential installation. Retail cost of rectangular units was circa £800 per m2 and shaped units (we have 3) were double that but we negotiated a substantial discount. Not sure what impact exchange rates will have had since then but, if your budget can accommodate it, SageGlass is such an elegant solution.

[Alexphd1]

7 hours ago, Adam2 said:

Good to hear. We met with a local who is doing a Nudura build (just finished concrete pour on top floor) who is also enthusiastic.

Our architect and their often used (hesitant to say preferred) SE firm are pretty negative about ICF through lack of experience - for example their response back to the architect is below - nothing is probably actually 100% wrong (though I don't recognise some of the issues/terms used!) but indicates their view. Needless to say, I'm talking with other SEs that have ICF experience.

1. The main concern on this project would be the waterproofing system.  With an ICF product, how would the product be guaranteed?  Typically the crack widths would need to be no bigger than 0.2mm.  These are controlled by the amount of reinforcement and the cover to the reinforcement.  With ICF both the amount of rebar that can be incorporated with the wall and the cover tend to be fixed or difficult to change.  How would the walls be checked to make sure that 0.2mm crack widths have not been exceeded.
2. The house has a lot of large openings.  These could be difficult to prove using ICF due to the fixed width of wall.  There are only so many bars that can be placed within a certain width of wall.  This could mean that steel beams and or columns are required, causing further issues with detailing around the interfaces between the two.
3. Care needs to be taken when installing kitchen and bathroom units as the fixings need to be taken through the polystyrene and into the concrete.  The insulation could compress causing the units to be un level and out of alignment.
4. Detailing of structural elements can prove difficult trying to comply with the detailing code. 
5. The system is advertised as low level skill required to construct the system but in reality tying of rebar and pouring of concrete are skilled jobs and need skilled labour to carry them out.

 

 

 

A few good questions, maybe start a new thread?