Benpointer

I started that way and it was a disaster. Low energy houses already place a strain on the control system of any heat source, split the house further to small heating zones just leads to short cycling and or a buffer and rubbish CoP without very careful design. One zone, no mixers or additional pumps, saves money, improves performance, makes it all easy. Interesting. We have multi-zone UFH in our current house and plan to do the same in our forthcoming new build. We like the en-suite in particular to be warmer (23°C) than the bedroom (18°C) or the living areas (21°C). I can't see why we'd want the whole house to be the same temperature.

So will you get your chosen TF company to create the drawings and submissions for Building Regs?

Thanks Dave, an interesting perspective and it may well be valid. I should say though that we do not have a clear picture of the design we are looking for in our heads. We do feel we need help translating our requirements and the constraints of the plot into a design that we can really commit to. I have tried to assemble the rooms we want into a design that works and I've struggled. We're happy to pay a bit extra for that creativity.

Interested in this topic as we have just got our first Architects quote (local RIBA practice). For plans only on a 160m2 house we are being quoted: Planning Approval design £9.4k + VAT Planning support to get through planning £1k + VAT Building regs approval drawings £7.5k + VAT Topographic survey, Ecologist, Arboriculturist, SE fees, Planning fees excluded. Heading towards £25k inc VAT, so probably 5-8% of the total build cost. Seems pricey to me but we did quite like the architect. We're actually struggling to find architects / architectural designers located in the south west who will do a modern design - some we have contacted have been slow to respond, which in itself puts me off using them. Any recommendations? We want someone based not too far away - in Wilts, Dorset or Somerset, ideally.

Is The Building Centre, Store Street, Bloomsbury, London - worth a visit? We're were thinking of going along for some ideas about the pros and cons of various construction methods but wondering if it may be just a promotion site for a few companies.

Good steer Alan, thanks - we're going to start talking to potential architects.

I don't think it's really a sensitive location, it's not national park, conservation area or anything else as far as I can see. There is nothing written in the PP Approval about PD rights. We've done a through the floor lift before. It's not a bad solution though you do lose a bit of usable space, of course. It's quite hard to fit them in a position that works well on both floors. When you add the space required on each floor for the lift and the space taken up by a stairwell, landing, etc. it's quite a lot of useable space lost.

In terms of working with the existing plans we have several issues: It's on two storeys and I am a full-time wheelchair user. Our current house is a chalet bungalow with two bedrooms and a bathroom that I can't get to - that's rather frustrating. The ground floor is circa, 100m2 - we want and will be paying for, rather more useable space than that. The existing design is exceedingly boring - if we're going to do this we want at least a bit of 'wow' factor in the finished house. I did ponder amending the current plans to remove the second storey and lower the roof to give a bungalow of 100m2... then apply for a 60m2 extension under permitted development rights (which I assume the new house will come with?). But overall it would seem simpler just to apply for the building we actually want.

Yes please could you PM me details? Thank you.

Great feedback already folks - many thanks. Interestingly, we have spoken to a local planning consultant in order to satisfy ourselves that we would have enough flexibility with the planning, before we exchange on the plot purchase. He was the one who suggested trying for a variation but to be fair to him he may not have appreciated how 'modern' a design we are seeking, nor how different from the current design we envisage it being. Will check out Fleming homes. Thanks all

Hi all, We have sold our house STC and have an accepted offer on a 0.85a plot with full permission for a 3-bed 160m2 chalet bungalow. We naturally want to do our own thing - we'd like a modern design, single story house of about the same area, 160m2 with the following features, so we expect to get a new design and apply for a planning variation. Features we want: High insulation levels and low energy use; target u-values of 0.12 max for walls, floor and roof. Light and airy inside Open plan living areas High ceilings including pent ceilings where appropriate Underfloor heating throughout ASHP Whole house MVHR Triple-glazed windows Solar PV panels and battery storage The design needs to be wheelchair-friendly - I'm a full-time wheelchair user. The plot is really good: edge of village, flat, easy access, electricity and water already on site. Only minor issues are that it's on clay and there's a mature oak tree about 5m inside next door's plot which will restrict where we can build a bit, but... 0.85 acre, so not a major issue. We want to self-manage using contractors (we know some good ones who we trust, from previous refurb projects). We're open to basing the project on a SIPS or timber frame build. What we need is somebody to create a design to meet our needs. We don't want to full architect route, we feel we're pretty savvy and don't need an expensive hand-holding. We're assuming we need someone who can: Produce the planning drawings and get it through planning. Produce BC drawings and specification and get that agreed with BC. Produce a design specification that a SIPS or timber frame company will be able to quote sensibly on and that our groundworks contractor can deliver to. Does that sound about right or are there other things we should be thinking about? Does anyone have a recommendation for a South West company that can deliver those design outputs? We're on the Dorset, Wilts, Somerset border. Thanks all!

To 'leave to silver' or not is a personal choice I guess - I can only say that our western red cedar has silvered beautifully over the past 14 years. Iwouldn't have it any other way. Not a cheap option these days though.

Sorry for the delay in replying - no, I am not monitoring the Ecodan's output or COP. I don't know how I would do that, sorry.

You say that now! We said similar 12 years ago having completed ours but guess what, we're just getting market valuations to sell and do another project. This time we'll get it right!

Neff induction hob in black granite island worktop. installed 13 years ago. Works for us. The granite was CNC-cut based on a CAD provided by Neff.

Problem solved! Somewhat embarrassingly, it's turned out to be a failed zone valve head on the UFH circuit - the microswitch not sending back to the FTC2 to trigger the ASHP pumps. New head fitted today - pumps now working! Thanks all!

The flow & return pumps definitely do work - they work if HW is being demanded. It just seems that the controller is not triggering the flow & return pump relay when UFH is requested. Hence my thought of putting the flow & return pumps on the same electrical circuit as the UFH pump. (That would mean the system would not work for DHW - but we never use it for that anyway.)

Regarding the flow and return pump. This is from the Ecodan Design, Installation & Servicing Instructions manual: "Each of the Ecodan® models require sufficient primary flow rate for adequate operation. Due to the large resistances caused by the plate heat exchanger in the Ecodan®, two domestic circulating pumps in series to produce the required flow rates. These pumps must be set to the same speed or damage to the system may occur." And this diagram:

I'd just like to reiterate (paraphrase) my original question - could put the flow & return pumps on the same circuit as the UFH pump? That would mean every time the UFH is demanding the ASHP flow & return will run. (It won't work for HW but we don't use that anyway.)

Yes. We can heat the HW and the ASHP flow and return pumps F&G switch on when HW is on demand. But no, we don't heat HW from the ASHP because (sigh) there is a long-standing issue where the controller errors every few days when trying to heat HW. We had someone look at this a few years ago and the upshot was, quote "It's a known issue with the FTC2, which is out of warranty and Mitsubishi won't fix, so you could either pay for a new controller or, since you have an immersion heater, use that". Which is what we have done ever since. It's not so bad as it sounds as we have solar HW too but still we are spending money on the immersion heater.

Q: Has it ever worked? Well, it's hard to be sure (because we have never actually checked that pumps F&G were spinning in the past) but the house has always able to maintain a good temperature even through periods of severe cold as in 2010, 2013 and 2018 (the 'beast from the east'). So I suspect it was working ok up until recently. Q: Why is there both a flow and return pump? No idea, I suspect the original plumber didn't really know what he was doing. I also suspect it's overkill but... that's not the issue at the moment - neither of the flow or return pumps are switching on when the UFH is on demand. (Edit: In fairness to the plumber, the Ecodan installation manual shows both a flow and return pump.) Re checking the wiring and controls: The pumps come on when the HW is on demand, so I think the wiring is ok. The FTC2 is probably at fault but Mitsubishi want £240 just for someone to come and have a look (!)

We have a fault with our Ecodan 85 FTC2 controller whereby the controller does not switch on the Flow and Return pumps (F&G on the schematic below) when the UFH is demanding. It does switch those pumps on when HW is on demand. Despite this, the UFH pump (E - which does power up as it's controlled directly from the UFH circuit, not the FTC2) seems to draw enough water through the ASHP to provide heating to the floors on most days. It seems to do this in short (5-10 min) cycles with the flow temperature quickly rising to meet the flow target temp, the ASHP cutting out, the flow temp dropping and the ASHP cutting in again. However, on cold days such as those experienced before Christmas, the heating is not reaching the room stat targets. I have a support query lodged with Mitsubishi for this but in case they fail to come back or simply say our system needs replacing, I have the following question for this forum: Is it safe to run the Edodan flow and return pumps even when the ASHP is not operating? (i.e. have the water circulating through the ASHP when the compressor is not running. If so, I could run these pumps off the same circuit as the UFH pump (E) because we don't use the ASHP to heat our hot water at all.

For what it's worth, ee did much the same to our 1960s bungalow: 100mm brick, 60mm cavity filled with blown polystyrene beads, 100mm brick, 2 layers of Kingspan K5 50mm on the outside with staggered joins, rendered over with K-Rend. We put fresh 12mm plasterboard on the inside in preference to re-skimming the rather flaky old plaster. No VCL fitted. We have had no damp problems at all. We do have whole house MVHR which helps prevent damp I believe. I will probably take a similar approach on our next project, maybe with even more insulation on the outside, depending on the heat loss calcs.

We put in a 3500l rainwater harvesting system when we did our house 12 years ago, for WC flushing, running the washing m/c and garden watering. I wouldn't do it again. Issues include: The water is of course unchlorinated, so you get brown toilet u-bends after a while (and the insides of the cisterns go black with mould, not that you see those of course). The washing never felt entirely 'clean'. We switched the toilets and washing m/c to mains after a few years for the above reasons. The tank ran out regularly each summer and the automatic top-up seemed to waste quite a bit of water down the tank overflow as it was delivered to the tank via the drainpipes and thus the leaf filter. The pump failed after 8 years and cost about £300 to repair (versus £700 to replace) The electric controller failed last year, so now we just switch the pump on manually when we want to water the garden. And it still runs out as soon as we have a dry period (ok we have a big garden and a lot of watering. So in short: nice idea but really not worth it. It's certainly never paid for itself. Sorry to be negative.

Very limited choice round here (north Dorset) but yes, I take your point. If anyone can recommend a good plumbing firm that knows something about underfloor heating and ASHPs near Shaftesbury, that would be great but it seems the vast majority of firms don't have experience of ASHPs and UFH.