1.5 Storey Cost Per Sq Metre

[Charlotte]

Hi, we’ve recently started looking into building a house in the Inverness area. The house we’re looking to build is modest, roughly 100/110 sq metres. Either 1.5 storey or bungalow. We’re now looking into costing the project to see whether it’s affordable for us. We’ve done a lot of research and it seems that 1.5 storey houses are the more economical option because of foundations, roof cost etc.

I understand that calculating costs on a 1.5 storey may be slightly more complicated than a simple bungalow. Would it still be accurate to use the internal sq meterage to calculate the cost even though the actual footprint is much smaller than that of a bungalow of the same sq meterage? This may be a silly question  but does anyone have any experience on estimating costs per sq metre for a 1.5 storey? I’ve read that the cost per square metre for the upper 1/2 storey is quite a bit less than the bottom storey.

[jamieled]

Welcome. I am just outside Inverness, around 40 mins west.

 

We are technically 1 and 3/4 storeys. Most people just refer to it as 1 and 1/2 though.

 

If it's outline costing, I'd just use floor area of ground and 1st floor together. The £/sqm costing approach is pretty rough - many site specific details and design choices can have a big influence. If it's more detailed costing then you'd just itemise the different elements (foundation, roof etc) and so the problem goes away.

 

Some TF manufacturers give kit prices, so you could look at the difference between bungalows and room in roof type houses to understand the cost difference for the structure alone? Then use the housebuilders bible to understand potential differences in standard foundation costs?

[ProDave]

Mine is going to come in at about £1000 per square metre but that is right at the bottom end of pricing as I have done so much of the work myself, so realistically expect to pay more.

 

the upper floor is not "free" The roof structure is more complicated than a basic cheap bungalow roof so probably not that much cheaper.

 

In due course as your plans evolve the forum can give you lots of advice.

 

And I am 23 miles north of Inverness.  I wonder where you are building? Do you have a plot yet?

[Charlotte]

1 minute ago, jamieled said:

Welcome. I am just outside Inverness, around 40 mins west.

 

We are technically 1 and 3/4 storeys. Most people just refer to it as 1 and 1/2 though.

 

If it's outline costing, I'd just use floor area of ground and 1st floor together. The £/sqm costing approach is pretty rough - many site specific details and design choices can have a big influence. If it's more detailed costing then you'd just itemise the different elements (foundation, roof etc) and so the problem goes away.

 

Some TF manufacturers give kit prices, so you could look at the difference between bungalows and room in roof type houses to understand the cost difference for the structure alone? Then use the housebuilders bible to understand potential differences in standard foundation costs?

That’s a good shout. I’ll have a look at that. We’re looking into getting some quotes from builders in the coming weeks anyway, just wanted to get an idea before we get the quotes back, thanks. 

[Charlotte]

1 minute ago, ProDave said:

Mine is going to come in at about £1000 per square metre but that is right at the bottom end of pricing as I have done so much of the work myself, so realistically expect to pay more.

 

the upper floor is not "free" The roof structure is more complicated than a basic cheap bungalow roof so probably not that much cheaper.

 

In due course as your plans evolve the forum can give you lots of advice.

 

And I am 23 miles north of Inverness.  I wonder where you are building? Do you have a plot yet?

The potential plot we’re looking at is about 20 minutes from Inverness. We’ve been given a very rough cost per square metre of £1500, as I said we’re looking for quite a basic finish that we can possibly upgrade later on. Should be getting quotes in the coming weeks, although it’s nice to get some insight before we take it any further

[ProDave]

1 minute ago, Charlotte said:

The potential plot we’re looking at is about 20 minutes from Inverness. We’ve been given a very rough cost per square metre of £1500, as I said we’re looking for quite a basic finish that we can possibly upgrade later on. Should be getting quotes in the coming weeks, although it’s nice to get some insight before we take it any further

If the plan is to build basic and upgrade later, get the basics of the build right, decent insulation and air tightness and go for a basic finish that you can improve on later.

 

Another popular plan is only complete the downstairs initially but get the structure of the building built for the rooms upstairs but leave them to do later.  My neighbour did that building a 1 bedroom bungalow initially and adding 3 upstairs bedrooms and another bathroom later.

[Mr Punter]

Some of your costs will be fixed no matter how many storeys, such as site preparation, planning fees, utility connections, drainage, and landscaping.

 

The 1.5 storey should be a little bit cheaper as there is less ground floor, foundation and roof per metre.

[Charlotte]

2 minutes ago, ProDave said:

If the plan is to build basic and upgrade later, get the basics of the build right, decent insulation and air tightness and go for a basic finish that you can improve on later.

 

Another popular plan is only complete the downstairs initially but get the structure of the building built for the rooms upstairs but leave them to do later.  My neighbour did that building a 1 bedroom bungalow initially and adding 3 upstairs bedrooms and another bathroom later.

I’ve heard that’s quite a popular way to do it. At this current stage the plan is to build the whole thing in one go. We’re going to prioritise insulation as, like you said, there’s not much point in it if the basics aren’t right! Air tightness and good insulation is definitely the way to go for long term savings.We’re hoping to save some money on the finishing side of it at the end, possibly put in a less expensive kitchen etc which can be upgraded later if need be.

[Charlotte]

8 minutes ago, Mr Punter said:

Some of your costs will be fixed no matter how many storeys, such as site preparation, planning fees, utility connections, drainage, and landscaping.

 

The 1.5 storey should be a little bit cheaper as there is less ground floor, foundation and roof per metre.

Yep I assumed that. I think at this point we’ve pretty much decided on a 1.5 storey as it will definitely look better on the site and the savings are a bonus. I’m grateful for any insight thanks, especially in this early stage 

[ProDave]

Assuming it's a rural plot, 1 or 1.5 storey is what the planners will expect, it's rare to be allowed a full 2 storey house outside the towns.

 

P.S are you already local to the area or are you relocating here?

[Charlotte]

1 minute ago, ProDave said:

Assuming it's a rural plot, 1 or 1.5 storey is what the planners will expect, it's rare to be allowed a full 2 storey house outside the towns.

 

P.S are you already local to the area or are you relocating here?

Yep very rare for Highland council to grant permission for anything more than a 1.5 storey which we’re happy with. We’re not looking for anything fancy. We’re local, the potential plot is just outside the village we currently live in. 

[stubiff]

Hi, we’re maybe looking at the Highlands. 
Is there any hard rule of what 1.5 storey actually is?

i.e. is there a max internal upstairs room wall height, say 1m or so. 

[ProDave]

50 minutes ago, stubiff said:

Hi, we’re maybe looking at the Highlands. 
Is there any hard rule of what 1.5 storey actually is?

i.e. is there a max internal upstairs room wall height, say 1m or so. 

Not really, it's up to the planners interpretation.

 

One near me got passed.  At the front of the house the rooms probably go to about 2 metres with just a small shoulder, and at the back the rooms are full height.  I think there was one token room above the garage that was a proper "room in roof"

[A_L]

53 minutes ago, stubiff said:

i.e. is there a max internal upstairs room wall height, say 1m or so. 

 

For the purposes of RdSAP/EPCs 1.8m is the maximum vertical wall height. Pages 118/9 here https://www.bre.co.uk/filelibrary/SAP/2012/SAP-2012_9-92.pdf

So I certainly would not go above this. 

[ProDave]

1 minute ago, A_L said:

 

For the purposes of RdSAP/EPCs 1.8m is the maximum vertical wall height. Pages 118/9 here https://www.bre.co.uk/filelibrary/SAP/2012/SAP-2012_9-92.pdf

So I certainly would not go above this. 

At 1.8M for most people that is a full height room.  so that might be a good point to aim for if you want unhindered headroom.

 

[stubiff]

24 minutes ago, A_L said:

 

For the purposes of RdSAP/EPCs 1.8m is the maximum vertical wall height. Pages 118/9 here https://www.bre.co.uk/filelibrary/SAP/2012/SAP-2012_9-92.pdf

So I certainly would not go above this. 

Thank you, very useful. 
Good to know that a near full height upstairs room is possible without having to add a lot more width to the footprint. 
i.e. 5m width downstairs can give a decent size room upstairs. 

[ProDave]

Our "wall" height upstairs is only about 1.2 metres.  But by building with "gable ends" rather than dormers, and using a cut roof hung from a ridge beam, so no unwanted internal timber structure, we get almost full standing room in all rooms. 

[stubiff]

Suppose the downside is that the roof windows would be too high for a view! (if wall is 1.8m)

 

[stubiff]

2 minutes ago, ProDave said:

Our "wall" height upstairs is only about 1.2 metres.  But by building with "gable ends" rather than dormers, and using a cut roof hung from a ridge beam, so no unwanted internal timber structure, we get almost full standing room in all rooms. 

Does that turn it into a 1.75, if you have vertical windows in those gable ends?

[ProDave]

Just now, stubiff said:

Does that turn it into a 1.75, if you have vertical windows in those gable ends?

I don't care what label anyone wants to put on it.  All I cared about was the planning was granted and it fitted in with all the other houses in the road.  If you wan't to call it 1.75 I will not argue.

 

You don't see this "gable end" style much here, i first noticed it on a trip to Skye and thought it made a lot of sense.

[stubiff]

Sorry, was meaning it more in relation to the planning, as you see quite a lot that say it has to be 1.5. 
Wondered if they said 1.5 on yours and then were happy with your plans. 

[ProDave]

I think the general planning policy here is 1.5 or 1.75 so it would not have mattered.

[Bozza]

In terms of keeping costs down with basic spec then upgrading later that could be a false economy.  As what you put in now spec wise is 20% cheaper during a new build, than anything you upgrade later, which would be liable for VAT.  
 

going up on a build is cheaper than going out.  Going from bungalow to 1.5 won’t be much more.

 

You’re  probably talking £1200-£1500 per sq m turnkey.  I built this 1.5 house, with a 1.4m combe height upstairs.  Highish spec slate roof etc, for that.

 

 

 

 

 

 

[Charlotte]

On 03/04/2021 at 16:13, Bozza said:

In terms of keeping costs down with basic spec then upgrading later that could be a false economy.  As what you put in now spec wise is 20% cheaper during a new build, than anything you upgrade later, which would be liable for VAT.  
 

going up on a build is cheaper than going out.  Going from bungalow to 1.5 won’t be much more.

 

You’re  probably talking £1200-£1500 per sq m turnkey.  I built this 1.5 house, with a 1.4m combe height upstairs.  Highish spec slate roof etc, for that.

 

 

 

 

 

 

Looks like a lovely house! I’ve heard a lot of people giving figures of £2500 a sqm or similar recently which really wouldn’t be affordable for us. Its putting us off slightly as we were advised that £1500-£1750 per sqm was a good figure to look at. 
Obviously we are aware that price per sqm isn’t the best way to estimate but it can give you rough idea. Its nice to hear of someone who has built for a cost similar to what we’d be looking at. Thank you so much for your insight, theres so much to learn and its good to hear from self builders themselves! 

[Charlotte]

On 02/04/2021 at 08:56, stubiff said:

Hi, we’re maybe looking at the Highlands. 
Is there any hard rule of what 1.5 storey actually is?

i.e. is there a max internal upstairs room wall height, say 1m or so. 

Hi! Just thought id say that its the specific area we are looking at in Highland that normally stipulates 1/1.5 storey. Its pretty strict where we are looking, i think it just depends on the area not just what council its in