Your thoughts...

[eandg]

Hi, we've worked our way through a few pads of tracing paper and settled on the attached floorplan (and have also included some elevations with indicative materials). Any thoughts on improving it?

 

We're limited to 200m2 by planning conditions and want to have:

 

• Ground floor - open plan-ish kitchen/dining/living with a separate playroom which could be used flexibly as kids (2 and 4) get older, a study/spare room and a downstairs shower room/wc (for future proofing) and a mudroom of sorts (which is a bit of a compromise as we've only got one entrance door - though the bi-folds in the dining will give direct access from the rear)
• First floor - a good-sized master with en-suite and dressing room, two decent-sized kids rooms which they can grow into, a bathroom for them and a flexible space which will act as a second sitting room but can be used flexibly in future (for art, music, exercise etc.) and could be converted into a fourth bedroom if required; and a balcony which can be accessed from the master and the flexible space

 

There's no door drawn into the master as we're still a bit unsure of placement yet. The front of our plot is due north (and the rear due south) so it has been designed to try and maximise the open plan living space to the rear with plenty of glazing. The balcony (and roof) overhangs by 1m to provide solar shading. We intend to crane in  shipping container and convert it into a summer-house-cum-store where we'll put anything that would ordinarily go in the loft into but we may still be a wee bit light on storage. 

 

Your thoughts please... 

Proposed floorplan.pdf

Materiality.pdf

[recoveringbuilder]

Personally I’d swap around the position of the downstairs wc/ mud room/ utility so that you’re coming in to the mud room first, I’d also want the playroom shut off somehow so that you have a tidy lounge for visitors, I know you’re having a seating area upstairs but with young children in bed at a reasonable time you would not want to be hosting guests outside their bedrooms, not sure about the positioning of the staircase you’d need to check out the headroom at that part of the house, that is just a thought since we had problems with this and that was with an architect drawing the plans!

[AliG]

The layout itself is broadly fine, you have more building issues.

 

You might well have fire risk issues with the kitchen open to the stairs.

 

As drawn the balcony would be a problem to build, it would require a lot of steel. The corner of the balcony outside bedroom 2 is above the kitchen then the whole outside wall upstairs would be above the living room and dining room. You would need very large steel beams to support the outside walls upstairs.

 

Similarly how do you support the joists for the upstairs rooms. Once you get spans much over 6m you start to have issues and the joists start to get thicker. In the area were the stairs are the joists would have no obvious support in either direction so again you would need beams in the ceiling.

 

I am not sure that the layouts of the utility room and bathrooms work well as drawn, you may find that in more detail you have some quite narrow spaces.

 

I would want a door on the utility room so as to reduce the noise of the washing machine. I also do not think you could get that much cabinetry in that size of room and still have room to work. Similarly the mud room is so small it would be better as a cupboard.

 

You may also need to find space for a boiler/MVHR/hot water tank etc depending on the services you expect to have.

 

 

 

[eandg]

Thanks both. AIG, why would the upper outside walls necessarily require lots of steel (they sit on the ground floor, not out from it which we had presumed would be fairly straightforward structurally). (And MVHR units seem to be about 600mm deep so had planned on siting this beside the washing machine and tumble dryer in the utility. 

 

Had planned on waiting for costs coming back and a design being agreed before appointing a structural engineer but may need to revisit! 

[AliG]

The wall along the balcony will be heavy due to being an outside wall, likely a wide cavity wall in most constructions. If an outside wall on the first floor is not directly on top of an outside wall below it then I would expect it to need supported on steel beams below. You cannot normally support an outside wall off the first floor joists. Further depending on the shape of the roof, the roof load will also be transferred down through this wall, further increasing its importance. I am by no means a structural engineer, but I think this would be an issue.

 

This wall looks to be approx 9m across, but there is no point at the left hand end to take the weight. Generally steel beams sit on the ground floor wall plate. So you would need an 13m beam to reach across the kitchen as well(I am estimating these lengths from the drawing which seems to be 1:100). Not only would such a beam be very expensive, but it would also be very thick and difficult to hide in the ceiling.

 

The build would be much simpler and cheaper if the upstairs wall was in line with the downstairs wall, but this would leave the shape of the house as somewhat boxy which I am guessing you are trying to get away from. Alternatively you could make the kitchen and bedroom 2 wider and then have the lounge and upstairs wall in line with a similar shape to that proposed.

 

You will get similar issues with placing the joists for the upstairs rooms, there are relatively few walls down the stairs to rest the joists on, so they may well need supported in other ways.

 

 I am guessing the utility room is around 1.8-m wide and 2.5m tall. You cannot put cabinets on three sides as there won't be enough room to work in the space in between them. By the time you open the door on a washing machine you need 80-90cm at a minimum to comfortably work and ideally more. You could probably do an L shape along 2 sides, but not three sides. I might be inclined just to use the long side.

 

As I say you can alter bathroom/utility room layouts from what are shown, but in general if you leave gaps of less than 90cm to pass through it could feel quite cramped. Also in all of these rooms you have to be very careful with window positioning, at various points you have windows above a bath, sinks and utility cupboards. You may want to make these windows smaller or they will limit where you can place things in the rooms.

 

I see you just posted about getting an SE. That is a good question. An architect designed my house, whenever i asked if things would be difficult to build, he said it would be fine - we ended up with £100k of steel. Normally an SE will advise on a finished design, you could then go back and adjust it if he thinks it will be difficult or expensive, but I think generally people just try and keep things in mind at first with the initial design. 

 

 

Edited May 27, 2019 by AliG

[eandg]

On 27/05/2019 at 14:02, AliG said:

The wall along the balcony will be heavy due to being an outside wall, likely a wide cavity wall in most constructions. If an outside wall on the first floor is not directly on top of an outside wall below it then I would expect it to need supported on steel beams below. You cannot normally support an outside wall off the first floor joists. Further depending on the shape of the roof, the roof load will also be transferred down through this wall, further increasing its importance. I am by no means a structural engineer, but I think this would be an issue.

 

This wall looks to be approx 9m across, but there is no point at the left hand end to take the weight. Generally steel beams sit on the ground floor wall plate. So you would need an 13m beam to reach across the kitchen as well(I am estimating these lengths from the drawing which seems to be 1:100). Not only would such a beam be very expensive, but it would also be very thick and difficult to hide in the ceiling.

 

The build would be much simpler and cheaper if the upstairs wall was in line with the downstairs wall, but this would leave the shape of the house as somewhat boxy which I am guessing you are trying to get away from. Alternatively you could make the kitchen and bedroom 2 wider and then have the lounge and upstairs wall in line with a similar shape to that proposed.

 

You will get similar issues with placing the joists for the upstairs rooms, there are relatively few walls down the stairs to rest the joists on, so they may well need supported in other ways.

 

 I am guessing the utility room is around 1.8-m wide and 2.5m tall. You cannot put cabinets on three sides as there won't be enough room to work in the space in between them. By the time you open the door on a washing machine you need 80-90cm at a minimum to comfortably work and ideally more. You could probably do an L shape along 2 sides, but not three sides. I might be inclined just to use the long side.

 

As I say you can alter bathroom/utility room layouts from what are shown, but in general if you leave gaps of less than 90cm to pass through it could feel quite cramped. Also in all of these rooms you have to be very careful with window positioning, at various points you have windows above a bath, sinks and utility cupboards. You may want to make these windows smaller or they will limit where you can place things in the rooms.

 

I see you just posted about getting an SE. That is a good question. An architect designed my house, whenever i asked if things would be difficult to build, he said it would be fine - we ended up with £100k of steel. Normally an SE will advise on a finished design, you could then go back and adjust it if he thinks it will be difficult or expensive, but I think generally people just try and keep things in mind at first with the initial design. 

 

 

Thanks for your comments - much appreciated. 

 

Would build route have any impact on the cost of incorporating a balcony/hiding any steel required and the relatively open floorplan - i.e. would it be easier to do so using ICF or brick and block than in timber kit or SIPs?

 

Having looked at A/GSHPs and MVHRs at the weekend we are definitely going to heed we are definitely going to heed your advice on the utility and make it into a bigger plant room - and maybe think about resiting it so that we don't have ugly vents out to the front of the house.

[AliG]

TBH I think this is where you need to speak to a SE.

 

Timber based build routes are lighter so an out of line upstairs wall would be easier to support, but I think the simpler thing is to alter the shape of the house slightly.

 

The issue of being open plan should be workable with a couple of beams across under the walls on either side of the flexible space upstairs. They can rest between the outside wall and the study wall at one side and the utility wall at the other. These would just be 4-5m long so should be fine. I think The issue would be that you will start to have criss-crossing beams if you also have to hold up the outside wall upstairs, once you fix that issue, the rest should be OK.

 

Good point on the vents, I have a neighbour with a utility room at the front of the house and exactly that issue.

[eandg]

3 minutes ago, AliG said:

TBH I think this is where you need to speak to a SE.

 

Timber based build routes are lighter so an out of line upstairs wall would be easier to support, but I think the simpler thing is to alter the shape of the house slightly.

 

The issue of being open plan should be workable with a couple of beams across under the walls on either side of the flexible space upstairs. They can rest between the outside wall and the study wall at one side and the utility wall at the other. These would just be 4-5m long so should be fine. I think The issue would be that you will start to have criss-crossing beams if you also have to hold up the outside wall upstairs, once you fix that issue, the rest should be OK.

 

Good point on the vents, I have a neighbour with a utility room at the front of the house and exactly that issue.

Thanks again. I am a bit bitwix and between on appointing an SE as the advise elsewhere is to use an SE with experience in your build method. I'll see if I can find someone for an informal chat and go from there. 

[AliG]

It might be that an architectural technical is the person who can help.

 

Presumably you will need someone to draw up the house anyway

[eandg]

10 hours ago, AliG said:

It might be that an architectural technical is the person who can help.

 

Presumably you will need someone to draw up the house anyway

 

Yes but depends on the build route/manufacturer as some provide drawing services as part of the package. 

 

We've had a quote from a SIPs company which seems to includes all glulam/steel beams specced by a structural engineer within the price, which may be interesting! 

[PeterW]

7 hours ago, eandg said:

We've had a quote from a SIPs company which seems to includes all glulam/steel beams specced by a structural engineer within the price, which may be interesting! 

 

Pretty standard with kit houses whether they are timber frame or SIP as the whole structure is engineered as one. It’s only standard brick / block that tends to use separate steel calculations. 

[eandg]

1 hour ago, PeterW said:

 

Pretty standard with kit houses whether they are timber frame or SIP as the whole structure is engineered as one. It’s only standard brick / block that tends to use separate steel calculations. 

Thanks - that's helpful. 

[andyscotland]

If you wanted to keep the balcony as-is, one possibility might be to build the external walls as though that was just a big window opening if you can picture that?

 

So you'd have a lintel over the top of it in line with the downstairs walls carrying the roof load, with the roof overhanging the balcony a bit. It would potentially be most economical/feasible with a corner post to support it.

 

Then the inset wall dividing the room and balcony would just be a stud wall, still insulated and weatherproofed, but lighter than a full structural external wall.

 

You might still need a little bit of steel below the balcony wall especially if there's a lot of glazing, or you might get away with it on the joists/any steel that might anyway be needed for the balcony cantilever. But it should be quite a bit thinner than if it had to carry all the roof loads as well. Making it cheaper and easier to hide in the ceiling downstairs.

 

I think could well be worth a short consultation with an engineer at an early stage to get a sense of the possibilities so you have the option to shape your design round them.

[eandg]

Thanks Andy - that would have some planning implications (as it would be considered as forming part of the GIA) so we'd need to cut back on space elsewhere. Think you and Ali are right and we definitely need to speak with an SE. Current plan will be to see which build route is best for us once estimates come back and we can compare spec and cost, then appoint an SE from there and redesign as required. 

[andyscotland]

Ah, that hadn't occurred to me. Seems a bit harsh to include it in GIA if it's actually external, even if the roof does overhang it!

 

Not saying that's wrong, I know very little about those rules, just commenting.

 

Sounds like a reasonable plan.