Buckinghamshire New Build

[Cheib]

Hi, we bought a relatively old house in May 2015. Bought with the intention of complete renovation but has since become clear that a renovation wiould be as expensive as a new build, luckily the house was de-listed about 15years ago (wouldn’t have bought it if it hadn’t been). Had a pretty dreadful refurb in the 70’s which meant only one external renovation was original (one side) and pretty much the only original thing internally is the cellar. 

 

We’ve had architects engaged for about six months and had a pre-planning meeting last week with the local planning office. Our intention is to move the house so sits more centrally in the plot, increase its height slightly to have better ceiling heights and have a separate garage and office/studio. Matters are slightly complicated by the fact that the boundary of the Green Belt and Chilterns AONB runs through the middle of our garden. New house will sit on but not in those boundaries. The good news is the planning officer was positive about what we want to do! 

 

Current house including garage is approximately 5500 sq ft. Intention is for the new house to be of similar size with perhaps also a basement. Will be contemporary (but not too contemporary!) with a lot of glazing on the ground floor. Design, construction method and materials not finalised yet! Want it to be ecologically efficient but not to Passivhas standards as I understand that’s expensive ? Will certainly have PV but whether we go down the road of GSHP or ASHP I am not sure, one of the things we need to work on. We have mains gas so I am not sure on the economies of them. I am a big believer on not wanting massive exposure to future utility prices so would rather invest now in insulation and M&E! We’re not currently connected to main sewerage but can be. Oh and there’s an old well in the garden which I am thinking of exploring its potential! 

 

Having had the successful planning meeting last week we have our first meeting for the final design next week. Excited but also nervous about what we’re taking on! 

[Nickfromwales]

Hi and welcome to BHub. 

Sounds like you’re asking the right questions at exactly the right time  

Fabric first approach will result in lower ongoing outgoings, but you need to decide how long you will reside there before writing any cheques.   

10 years minimum on most renewables is a reasonable break-even estimate, but after that is really when you start to reap the rewards. 

Build airtight and go for MVHR either way as you can just burn gas if it’s a shorter term plan. If you’re leaving there on your back then time to decide whether to pay the utility’s companies forever or spend that on yourself and become energy wise. 

 

Grab a chair, a beer and some Nurofen, will be a steep learning curve but worth every minute you invest in making these decisions before it’s too late to change.

 

Its not more more expensive to build passive per se but there is far more detail and attention required. You can mitigate against a HUGE amount of that worry by going for a TF / other supplier who will take you from slab through to the roof lights. Some of these will guarantee the air tightness test results so if you’re a novice then this has some serious attraction. 

Leaves you with only the M&E to worry about, and which kitchen to fit   

Ask lots of questions, the answers are free and impartial here. 

Good luck  

 

[Mr Punter]

Morning and welcome.

 

At 5500ft2 that is an enormous house. At that size, you will need to be very careful about what is specified, as the impact on the budget will be large and anything less than a 5 star hotel standard finish will not do it justice.  I assume you are not considering physically taking on the build?

[Bitpipe]

You're doing pretty much exactly what we did - demolish an existing and build new with basement. We're in Berkshire also on mains gas - 440m2 inc garage. You're welcome to come visit if you want to PM me.

 

As Nick says, if you want to reduce dependency on future fuel prices then build a well insulated, airtight home with consideration to effective heating and cooling.

 

I don't think anyone on this forum has a passive certified house but many of us have built to passive principals in order to achieve the same objectives as you and the cost is nominal compared to standard construction.

 

I ran our numbers yesterday for another thread and we spend £1.2/day on gas and £1 on electric (after PV FIT) for our house which is occupied through the day as we both work from home. Teenage kids etc..

 

Most important thing is the design - the house needs to be considered as a system, not a pretty box with services thrown in as after thoughts. Your architect may or may not have the skills to do this but it's not rocket science and many here have figured it out.

 

@HerbJ has a similar area to you I think - we used the same firms in the build but both PMd the projects ourselves (in my case with zero prior experience).

 

It can be done

Edited January 19, 2019 by Bitpipe

[newhome]

Hi and welcome to BuildHub. 

 

Others have already made lots of great comments above but if you are concerned about the budget it may be advantageous to post a draft of your plans here. That way people can comment on them both from a ‘how practical is this to live in’ perspective as well as a ‘how much will this cost to build’ perspective. An architect may not always have those things at the forefront of their mind. For example lots of complicated angles etc. can increase the build cost somewhat. You may need a thick skin for that as sometimes the responses can sound a bit brutal but it’s your house and your build and ultimately your decision. Better to have comments at an early stage however than to maybe regret not changing something later. Personally I think most comments are useful even if it’s just to validate why you won’t be using the suggestion. Sometimes even a seemingly minor change can make a big difference to either costs or overall comfort. 

 

That said a 5500 square foot house (or a shade over 500 square metres in new money) will require some fairly hefty cash. What sort of figure do you have in mind to achieve that size of build? Costs vary quite a lot but given the area of the country you are in and the finish needed I imagine you are talking about something in the region of 1500 to 1800 a square metre? Others on here have have achieved their builds for less than that although this has generally meant quite a lot of personal input, and some have gone north of 2k per square metre. 

[Ed Davies]

3 hours ago, Cheib said:

but not to Passivhas standards as I understand that’s expensive

 

It's worth considering that Passivhaus, or at least building to roughly Passivhaus standards, tends to be proportionally less expensive the larger the house is because some costs are fixed and because some costs are proportional to the external surface area of the house which increases more slowly than the volume as dimensions are increased.

[Cheib]

5 hours ago, Nickfromwales said:

Hi and welcome to BHub. 

Sounds like you’re asking the right questions at exactly the right time  

Fabric first approach will result in lower ongoing outgoings, but you need to decide how long you will reside there before writing any cheques.   

10 years minimum on most renewables is a reasonable break-even estimate, but after that is really when you start to reap the rewards. 

Build airtight and go for MVHR either way as you can just burn gas if it’s a shorter term plan. If you’re leaving there on your back then time to decide whether to pay the utility’s companies forever or spend that on yourself and become energy wise. 

 

Grab a chair, a beer and some Nurofen, will be a steep learning curve but worth every minute you invest in making these decisions before it’s too late to change.

 

Its not more more expensive to build passive per se but there is far more detail and attention required. You can mitigate against a HUGE amount of that worry by going for a TF / other supplier who will take you from slab through to the roof lights. Some of these will guarantee the air tightness test results so if you’re a novice then this has some serious attraction. 

Leaves you with only the M&E to worry about, and which kitchen to fit   

Ask lots of questions, the answers are free and impartial here. 

Good luck  

 

Thanks for all the replies...haven't quite got the hand of quoting multiple replies so I'm starting here.

 

Interesting what you say about Passiv not being more expensive. First naive question....what's a TF ?!

 

With regards to renewables our intention is to live in this house for at least 20 years so we can take a long term view. Although I do think the housing market will really start to reflect the running cost of house in the next five to ten years as utility costs continue to climb especially with big houses. There are an awful lot of houses in the area we live in that were build in the 80's and 90's which people want top money for and I think are just hugely mis-priced....the have poor insulation, traditional heating systems and out of date layouts which I think mean these houses will be valued more on what the plot is worth than the house....because the only buyer will be someone that wants to start again.  Which is what we're now doing.

 

 

5 hours ago, Mr Punter said:

Morning and welcome.

 

At 5500ft2 that is an enormous house. At that size, you will need to be very careful about what is specified, as the impact on the budget will be large and anything less than a 5 star hotel standard finish will not do it justice.  I assume you are not considering physically taking on the build?

No definitely not taking on the build! Have no experience in this field myself. I have quit full time work though so intend to "some extent" (to be decided how much) get involved in Project Management. We did a full refurb of our house in London ten year's ago and learnt a lot the hard way regarding that. Wouldn't say it's made me an expert but I know a lot more than I did about dealing with these things.

5 hours ago, Bitpipe said:

You're doing pretty much exactly what we did - demolish an existing and build new with basement. We're in Berkshire also on mains gas - 440m2 inc garage. You're welcome to come visit if you want to PM me.

 

As Nick says, if you want to reduce dependency on future fuel prices then build a well insulated, airtight home with consideration to effective heating and cooling.

 

I don't think anyone on this forum has a passive certified house but many of us have built to passive principals in order to achieve the same objectives as you and the cost is nominal compared to standard construction.

 

I ran our numbers yesterday for another thread and we spend £1.2/day on gas and £1 on electric (after PV FIT) for our house which is occupied through the day as we both work from home. Teenage kids etc..

 

Most important thing is the design - the house needs to be considered as a system, not a pretty box with services thrown in as after thoughts. Your architect may or may not have the skills to do this but it's not rocket science and many here have figured it out.

 

@HerbJ has a similar area to you I think - we used the same firms in the build but both PMd the projects ourselves (in my case with zero prior experience).

 

It can be done

 

That's very interesting thanks and I'd be interested in learning as much as possible, if you have an hour or two to spare I'd love to take you up on your offer. I understand what you're saying I think about a house being a system....one thing that is absolutely key for me is trying to future proof it too. For instance I've been reading about rainwater harvesting....not sure we'd go there yet but I think you can plan for it/have the pipework system in place and switch to it in the future if you want to.

 

The one thing that REALLY concerns me about the project is making sure the house works properly and that it's been specified properly. e.g.

 

Architect Designs House

House is modeled for heating requirements based on glass area, orientation, construction type, insulation etc

M&E engineer specifies system

Contractor installs system

 

If it doesn't work properly/house is too cold who do is responsible ? I guess it's down to the contracts.

 

 

4 hours ago, newhome said:

Hi and welcome to BuildHub. 

 

Others have already made lots of great comments above but if you are concerned about the budget it may be advantageous to post a draft of your plans here. That way people can comment on them both from a ‘how practical is this to live in’ perspective as well as a ‘how much will this cost to build’ perspective. An architect may not always have those things at the forefront of their mind. For example lots of complicated angles etc. can increase the build cost somewhat. You may need a thick skin for that as sometimes the responses can sound a bit brutal but it’s your house and your build and ultimately your decision. Better to have comments at an early stage however than to maybe regret not changing something later. Personally I think most comments are useful even if it’s just to validate why you won’t be using the suggestion. Sometimes even a seemingly minor change can make a big difference to either costs or overall comfort. 

 

That said a 5500 square foot house (or a shade over 500 square metres in new money) will require some fairly hefty cash. What sort of figure do you have in mind to achieve that size of build? Costs vary quite a lot but given the area of the country you are in and the finish needed I imagine you are talking about something in the region of 1500 to 1800 a square metre? Others on here have have achieved their builds for less than that although this has generally meant quite a lot of personal input, and some have gone north of 2k per square metre. 

 

If we could achieve build costs in the £1500 to £1800 sqm I'd be very happy, I have been told to expect more. One thing I learnt when we did our refurbishment in London is that if you set a high bar in terms of fittings/flooring etc things can get very expensive very quickly.  To keep the expensive angles down we're going for a barn style (i.e. rectangular box)....our architect has done a couple of incredible houses with roofs that are almost organic in form but costs are huge for that !

 

I have a thick skin so will post plans when we get them....at the moment they're a work in progress. I think our architect is very strong on design  (they've designed several Para 55 houses) but I suspect less good on practicalities. I'm happy to take on all advice or criticism! My cousin is an architect and I think a very practical one but is based in Ireland and doesn't have the time to take on our project. He's already volunteered to have a look at the plans and especially comment on how he thinks the house will work/flow. We currently have children of primary school age but they'll soon be teenagers so our use of the house will change and the house needs to adapt to that. There's also every chance that they may end up living with us into their early 20's/post Uni as that seems a very strong trend these days due to the cost of housing in S.E. England.

 

1 hour ago, Ed Davies said:

 

It's worth considering that Passivhaus, or at least building to roughly Passivhaus standards, tends to be proportionally less expensive the larger the house is because some costs are fixed and because some costs are proportional to the external surface area of the house which increases more slowly than the volume as dimensions are increased.

 

Very good point and hadn't really considered that. In theory there should be economies of scale.

[newhome]

2 minutes ago, Cheib said:

First naive question....what's a TF ?!

 

TF is timber frame 

 

There is a glossary of the more common acronyms here although interestingly that one isn't there (@ProDave) 

 

 

[ProDave]

9 minutes ago, newhome said:

 

TF is timber frame 

 

There is a glossary of the more common acronyms here although interestingly that one isn't there (@ProDave) 

 

 

It is now.

[Ferdinand]

*Waves*

Welcome to the pleasuredome.

 

F

[Bitpipe]

2 hours ago, Cheib said:

 

That's very interesting thanks and I'd be interested in learning as much as possible, if you have an hour or two to spare I'd love to take you up on your offer. I understand what you're saying I think about a house being a system....one thing that is absolutely key for me is trying to future proof it too. For instance I've been reading about rainwater harvesting....not sure we'd go there yet but I think you can plan for it/have the pipework system in place and switch to it in the future if you want to.

 

The one thing that REALLY concerns me about the project is making sure the house works properly and that it's been specified properly. e.g.

 

Architect Designs House

House is modeled for heating requirements based on glass area, orientation, construction type, insulation etc

M&E engineer specifies system

Contractor installs system

 

If it doesn't work properly/house is too cold who do is responsible ? I guess it's down to the contracts.

 

No problem, early feb would work for me - @HerbJ is down the road and @Jeff is not much further. @Weebles are also in the area and are in the midst of building so you may want to PM them to see if any are open to a visit.

 

You'll find that self builders are more than happy to talk about their experiences. Getting them to shut up is the hard part. I found visits to other builds, complete and in progress, invaluable.

 

To your last point - you're responsible. Don't rely on a contract to get you out of a hole. I'd be wary of paying for M&E engineers - find a good plumbing contractor and a good electrician and get them to design and install their own systems.

 

Also don't rely on the architect, however talented, to design you a house that you can either afford to build, is actually buildable, will be comfortable to live in or economical to run.

 

The first two parts of your process there should happen in parallel.

 

If you've experienced some building projects already then you're already streets ahead of where many of us were when we started!

 

p.s. Rainwater harvesting done cheap is good for watering the plants, different story wanting to use it inside your house....

Edited January 19, 2019 by Bitpipe

[Nickfromwales]

5 hours ago, Bitpipe said:

I'd be wary of paying for M&E engineers - find a good plumbing contractor and a good electrician and get them to design and install their own systems.

Not entirely sold on that statement, biased as I may be. I have heard plenty of woes where there was little or no synergy between 'fellow trades'.

 

8 hours ago, Cheib said:

M&E engineer specifies system

Contractor installs system

Unless you intend to PM them and make sure that there is constant and recognised dialogue between trades, don't expect that to 'automatically' go well. It will require your continued intervention and constant double-checking that things are being executed as promised.

Asking questions and including the replies in the contracts will be your parachute. Tell the chosen professionals that you will expect the systems to work, exactly as they have been asked to, as in what they promised when they quoted to supply them as fit for the described purpose. Assumptions will kill you dead, and trades will hang onto those for dear life for defence if / when you overlook things and don't cement them as the expected criterium. 

This can be very easy, or very hard. Many on here report varying mixed bags of results, but the information is here by the bucket load if you wish to search for it. The good news is people here have shared the good / bad / and downright life-changing ugly, from which you and others may benefit. I know I have  

Fill your boots  

[Bitpipe]

11 hours ago, Nickfromwales said:

Not entirely sold on that statement, biased as I may be. I have heard plenty of woes where there was little or no synergy between 'fellow trades'.

 

Unless you intend to PM them and make sure that there is constant and recognised dialogue between trades, don't expect that to 'automatically' go well. It will require your continued intervention and constant double-checking that things are being executed as promised.

 

OK, to clarify

 

I did have a clear idea of what outcomes I wanted (mostly based on ideas from this forum) and brokered discussions between these two trades (plus MVHR if you're not DIYing that element - something of a rite of passage on this forum) to ensure they were on same page, especially where they interacted (such as heating system, fighting for first fix space, etc).

 

I more or less left it to them and their professional judgement to design their respective systems and decide where each pipe and cable went - can't help thinking that if I had commissioned a super detailed wiring / plumbing diagram then I would have been spending twice and/or it would be ignored anyway.

 

We also did a few site walk throughs ahead of 1st fix to make sure large services, such as foul runs, went where they could/should and didn't clash with other systems.

 

One place where a M&E plan would be useful is during the structural design to ensure sufficient voids, steel penetrations etc are made to enable the bulky services (MVHR, Fouls etc) to be laid efficiently. We got caught out a few times on that but managed to work around issues - just.

[Cheib]

On 19/01/2019 at 23:52, Nickfromwales said:

Not entirely sold on that statement, biased as I may be. I have heard plenty of woes where there was little or no synergy between 'fellow trades'.

 

Unless you intend to PM them and make sure that there is constant and recognised dialogue between trades, don't expect that to 'automatically' go well. It will require your continued intervention and constant double-checking that things are being executed as promised.

Asking questions and including the replies in the contracts will be your parachute. Tell the chosen professionals that you will expect the systems to work, exactly as they have been asked to, as in what they promised when they quoted to supply them as fit for the described purpose. Assumptions will kill you dead, and trades will hang onto those for dear life for defence if / when you overlook things and don't cement them as the expected criterium. 

This can be very easy, or very hard. Many on here report varying mixed bags of results, but the information is here by the bucket load if you wish to search for it. The good news is people here have shared the good / bad / and downright life-changing ugly, from which you and others may benefit. I know I have  

Fill your boots  

 

I think that’s very good advice about making sure the contract specifies that systems will work and perform to specification. I have a decent amount of experience of contracts with suppliers/consultants from my day job so have an idea how to manage it but hadn’t thought about it, I’m fully aware that as an individual the T’s &C’s in a contract will be full of caveats and reductions in liability so that’ll all be getting removed,