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Experience - New Build / Complete New Heating System

Air Source Heat Pumps (ASHPs)

Last Post by ASHP-BOBBA 3 months ago

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vincro

(@vincro)

New Member Member

Joined: 4 months ago

Posts: 3

Topic starter 11/01/2026 5:29 pm [#2729]

We are in the process of completing a new build project in East Anglia for which we have "decided" (thanks architect) to install an ASHP.

For the benefit of others, I want to start detailing (with updates to this post) the process/experience here, and see if I can help, and learn as I go along.

As a starting point, the project is a:

Complete new build, meeting 2025/26 build regs
200sqm, with 140sqm of UFH

Initial Attempt at a Quote: Nu-Heat

Back in October the contractor's plumber had arranged for Nu-Heat to come on site, and after a discussion of an hour or two between myself, the plumber, contractor and Nu-Heat, as well as a sharing the floor-plan, elevations and wall build ups, they came with a super high level quote of:

51w/sqm heat loss
16KW Nibe or Panasonic ASHP (not even a model)
300L cylinder
Cliptrack system
Install and Support Package

In the intervening period, I had spent too much time on the RHH forums, and queried the quote which lacked any detail. The result of this, was that I was given the spec of the machines (Nibe 2040 or perhaps 2050 depending on supply, and Panasonic Aquarea, or possibly Aquarea TCAP), I was also told that the Heatloss was guestimated at 51w/sqm, which, unless my math is wrong, would imply a very high level of heat-loss.

Finally, they followed up by asking for detailed insulation information, and possible SAP report -- not possible given the half built state, and unlikely to be done unless we finish the house and then think of doing one and then getting quotes for the ASHP. We are now waiting for an update, and more accurate quote, although in the intervening period, I had been told that the heat loss numbers are unlikely to change (which seems like an odd assertion.)

Second Miss-Attempt(s) at a Quote: Heat Geeks & EON

In the meantime, whilst waiting, and with too much time in the run up to Christmas, I filed a request for a quote from Heat Geeks. This took till after the new year for them to reply and state that they were unable to provide service for a new build project, and would recommend the engineer I had reached out to already waiting for them to respond, which brings us to the third attempt.

I had also called EON Next, our existing energy provider, and they said they could not help, as they only do retrofits.

Third Attempt at a Quote: Smart Heating Solutions

Having waited too much, I reached out to Smart Heating Solutions (Heat Geek Network), whom responded quickly, asking for a bunch of detail, which you would have thought Nu-Heat could also have asked for to make a better and more proper initial assessment of heat loss. They suggested they would come back quickly, but Christmas needless to say got in the way. i had to follow up a second, and a third time, when finally, they provided a detailed quote using the Spruce quotation system, with an itemised breakdown. The kind of thing I would expect of any quote really:

6.7KW heatloss
40 degree flow temp
413% efficiency
7KW Vaillant AroTherm+
250L cylinder
UFH install
Materials etc
BUS administration

Having read a recent and decent/comprehensive review of the AroTherm+ on RHH Forums, and the support provided by Vaillant for their systems, it also gave additional hope and promise for this quote/system, neither of which could be said for the Nibe or Panasonic systems.

Fourth Attempt at a Quote: Heat Different

Having come across Heat Different's name on the RHH Forum, and reviewed their works and recommendations, as well as seeing the award they received for the water source heat pump they installed at a project nearby, and whilst playing the wait-wait-waiting game, I reached out to Heat Different, and supplied them with the details that I had also shared to Smart heating Solutions and Nu-Heat. They then proposed a site visit. This is pending this week, so we shall see. I am hopeful.

As it stands, as of Jan 11, 2026, we have:

One quote with a range of £10.5-£13.5K between 2 16KW options plus cylinder, with additional costs for the UFH cliptrack and install of £3K and £1200 respectively. The cost of installation "unknown" unless the plumber doing the rest of the work provides a fixed price or correct estimate.
One quote for a the Vaillant and cylinder for about £6250 plus complete installation, materials bring us to ~£30K before BUS etc.

We hope to have another quote and to be able to compare heat loss calculations before the end of the month, but with everything being so slow, I do wonder.

More updates soon.

This topic was modified 3 months ago 6 times by vincro

This topic was modified 3 months ago 2 times by Mars

Quote

Mars

(@editor)

Illustrious Member Admin

Joined: 5 years ago

Posts: 4516

11/01/2026 9:26 pm

Welcome to the forums @vincro and good luck with finalising your proposals and quotes. Also look forward to your updates.

One thing I've started recommending to all homeowners is to get an estimate from OVO alongside quotes from other installers as a useful sanity check on system sizing, costs and overall approach because their assessment process is quite good from what I've heard.

You can request an estimate here: https://solar-and-heating.ovo.com/heat-pump-survey/estimate/select-address?utm_source=renewable_heating_hub&utm_medium=partner&utm_campaign=estimate_journey_hp&utm_id=renewable_heating_hub

As always, the aim is to help you make a better-informed decision and avoid costly mistakes further down the line.

If you have any questions about the quotes you receive or want a second opinion, feel free to reply to this email.

Get a copy of The Ultimate Guide to Heat Pumps

Subscribe and follow our YouTube channel!

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JamesPa

(@jamespa)

Illustrious Member Moderator

Joined: 3 years ago

Posts: 4714

11/01/2026 9:53 pm

Newbuild 200sq m house, 16kW? Somebody is having a laugh at your considerable expense. Either the construction standard is appalling or the loss is way out.

My 1930s 200sq m house with partial iwi on otherwiise solid walls, uninsulated floors, double glazing and 300mm loft insulation, and a couple of modest 1980s extensions, is 7kW at -2, confirmed by measurement. Heat geek have got it right or thereabouts although even 7kW may be over cooking it depending on where you are.

Give the 16kW guys a wide berth. If they get this so wrong imagine what the workmanship will be like.

This post was modified 3 months ago 2 times by JamesPa

4kW peak of solar PV since 2011; EV and a 1930s house which has been partially renovated to improve its efficiency. 7kW Vaillant heat pump.

😢

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vincro

(@vincro)

New Member Member

Joined: 4 months ago

Posts: 3

Topic starter 11/01/2026 10:06 pm

@jamespa I would wholeheartedly agree with you.

In all the videos of @editor, I never recalled anyone talking about such HUGE pumps. Certainly a rarity rather than the norm. It was one of a few red flags, and hence why, despite the recommendation from the contractor's plumber we started looking elsewhere.

We have some large floor to ceiling windows, a few tiny single glazed windows (don't ask) and otherwise insulated with celotex and more through the wazoo.

The next question is, even with the right size pump can the system be designed properly.

Thanks for pitching in on your Sunday evening =)

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Bash

(@bash)

Reputable Member Member

Joined: 7 months ago

Posts: 187

11/01/2026 10:18 pm

@vincro

We have a similar sized 1950's semi with a 2005 extension, lots of glass and an open fireplace.

Our heat loss was calculated at 6.2kw and testing this before our HP install later this month by turning down our gas boiler confirms this.

16kw unit for a new build is ridiculous!

👍

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vincro

(@vincro)

New Member Member

Joined: 4 months ago

Posts: 3

Topic starter 11/01/2026 10:36 pm

@bash you and me both, can agree.

Nothing like shooting yourself in the foot.

Common sense would tell you that someone with the wherewithal to build a property, would have an eye for detail, and plucking heat loss figures out of thin air would not instil confidence.

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JohnnyB

(@johnnyb)

Estimable Member Member

Joined: 1 year ago

Posts: 114

12/01/2026 12:47 am

Your sap clculations should give you a heat loss figure. I don't know how and from what part of the form to get the information but it is in there.

I'm in the process of a self build, similar size house with downstairs UFH and upstairs rads in bedrooms and UFH in bathrooms. Our heat loss from the heating engineers is 4.3kW and they checked this againest the SAP calculations which was slightly less. When they worked out or heat loss they used the current building regs U values not the actual numbers used in the SAP calcs.

We have decided to fit a 5kW Samsung. It is going in this week so I should soon be able to tell you if it heats the house easily or not.

The newbuild opposite ours has a 12kW unit in a slightly smaller house. When I heard this I asked our installers to double check the numbers and that is when I sent him the SAP calcs and he told me that showed a slightly lower heat loss than he had allowed, I think 4.1. You can't meet current building regs and need a large heat pump. They initially suggested a larger unit to heat the hot water quickly as I have a 300 ltr tank, but the next size up from Samsung is an 8kW unit which is a restricted larger unit anyway so I decided that wasn't what I wanted.

Installing a heat pump is a good idea so do thank your architect. With a new build and so much UFH you only need a small unit and it will be able to run at really low flow temperatures so it shouldn't be expensive to run, unless it is installed/set up badly or overspecced. We are currently living in another house on site that we built the year before. It is a smaller house, 135 sq mtrs, and the 5kW HP we have for that keeps it warm very easily with several hours during the day when the HP is switched off as the house is up to temperature.

👍

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ASHP-BOBBA

(@ashp-bobba)

Honorable Member Member Professional Installer

Joined: 1 year ago

Posts: 440

12/01/2026 10:32 pm

@vincro I would be surprised if it is much above 5 to 6kW, we have just completed a brand new 244m2 building in October last year with a heat loss of 6.9kW and it held the home at 22 deg C the whole time when outside was -1 to -6 for the last 2 weeks. we installed an 8kW Ecodan as this was the closest capacity in their range and it runs around 95% capacity in winter.

AAC Group Ltd covering the Kent Area for design, supply and installation of ASHP systems, service and maintenance, diagnostics and repairs.
Professional installer. Book a one-to-one consultation for pre- and post-installation advice, troubleshooting and system optimisation.

👍

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