Detailed design after planning permission

[Babak]

Hello

 

I have the planning permission and am planning to proceed to the build phase. My own architect cannot help the end of August at the earliest and I would like to book the builders ASAP given the lead times. I plan to use ICF for walls and a related product from the same guys for the roof structure (Thermohouse). I also know the material types to be used elsewhere (eg type of render, first floor posi joist depth, opening dimensions, etc.

 

Please can anyone help with the following:

 

- Apart from the structural calculations and drawings and the building regs, what details are necessary before I can proceed to build the house fabric?

- The only things that I can think of I need ASAP is where the services (electricity, water only) get in, and the waste pipes going under the building to connect to sewage, in particular the relevant elevations, etc, to make sure the sewage/waste pipe downward gradient is maintained all the way. Also possibly the height/elevation calculations so that with various layers added to the foundations, (floor/isolation, screed), my ceiling to floor distance is maintained at 2.4m.

- I can deal with the wiring, socket locations, MHRV ducts, etc at a later stage and have thought of the potential issues, and how to solve them. 

- My thoughts are that the structural engineer will calculate based on my chosen material and their specs (type of ICF, roof, etc), work out where the support beams will have to be, then the foundation requirements, etc, and then draw the design to enable the build of the foundation and the building fabric, and this should also include where the waste pipe goes/its gradient (my biggest concern). 

 

- I have contacted two other firms of architects, and they are quoting £4K and £15k (yes) for a complete design drawing package, the latter of the two will also a little project management as well. These exclude structural engineer fees, so am baffled why the costs are so high.

- I just cannot understand what it is that will take such huge fees to design though. Please, what am I missing here?! AM I being stupid for thinking £4K is silly?

 

If anyone has suggestions in terms of who I can go to to get my drawings finalised I will hugely appreciate.

 

Finally, one of my planning conditions is not to commence development above the slab level before external material has been approved. Am I right in presuming that I can still demolish?

 

Thank you!

 

 

 

[saveasteading]

Where in the country? 

The processes and consequences can be very different.

[Babak]

 

41 minutes ago, saveasteading said:

Where in the country? 

The processes and consequences can be very different.

Southeast England in Maidenhead.

[saveasteading]

1 hour ago, Babak said:

Finally, one of my planning conditions is not to commence development above the slab level before external material has been approved. Am I right in presuming that I can still demolish?

Yes you can take this literally. as long as other conditions don't say 'no work to start...' etc.

And so you could also do underground work, up to slab level as far as planning is concerned, ....but that needs building reg's.

 

£4k is not silly. not silly low anyway. Feasible as you say you will be doing a lot yourself, but don't expect much hand-holding, or to include many changes of mind.

The building inspector is unlikely to  help either, so your  own drawings will have to be technically complete and competent.

 

£15k sounds a lot, and should cover the whole of the project management...you just keep paying the builders.

But check that it does include that. Berks way, there are varying expectations on income. Perhaps your  £15k has to pay for the chalet in France and the pony club.

 

You get what you pay for except when you don't.

 

It does sound from what you say that you do need a fair amount of professional help with this, and it costs.

 

What is your worry with the waste pipe gradient?

[Babak]

43 minutes ago, saveasteading said:

Yes you can take this literally. as long as other conditions don't say 'no work to start...' etc.

And so you could also do underground work, up to slab level as far as planning is concerned, ....but that needs building reg's.

 

£4k is not silly. not silly low anyway. Feasible as you say you will be doing a lot yourself, but don't expect much hand-holding, or to include many changes of mind.

The building inspector is unlikely to  help either, so your  own drawings will have to be technically complete and competent.

 

£15k sounds a lot, and should cover the whole of the project management...you just keep paying the builders.

But check that it does include that. Berks way, there are varying expectations on income. Perhaps your  £15k has to pay for the chalet in France and the pony club.

 

You get what you pay for except when you don't.

 

It does sound from what you say that you do need a fair amount of professional help with this, and it costs.

 

What is your worry with the waste pipe gradient?

LoL, yes I am sure there will be a second home somewhere!

 

Regarding the soil pipe, I will have a run of about 24 meters from the manhole near the site boundary to the furthest vertical section. Therefore I will not have a huge margin to play with the slab level, given the drop ratio of about 1:50 ish. As I have a height restriction and trying to maximise floor area in the attic, I just need to make sure the slab level is just right to accommodate a soil pipe underneath but not be too high to reduce the ceiling headroom. I think the calculation is pretty easy, but is one of those things I would like a professional to do - no room for errors involving a soil pipe here!!!!

 

Looks like I have to cough up the £4K, thank you!

 

 

Edited July 6, 2021 by Babak
Typos

[saveasteading]

To some Architects and Engineers this will be very easy to do , and they don't need much time to do it, so you will get what you need at a decent price.

To others everything is like a new invention, and takes too long, and they charge you more.

 

In other words I think, use someone who does this sort of house as a matter of course, not someone who says they can do anything...their expertise, or need for it,  is spread too far.

and you must tell them clearly that you are not looking for amazing ideas, just a house that works.

[Scoobyrex]

Look for a recommended Architectural technician (Not Architect) that works closely with a structural engineer.  Or ask your structural engineer for a recommendation.

The architect technican can get the current drawings ready for the Structural Engineer if your original architect is willing to share the files.

 

My quotes ranged from 4k to 22k. 

 

The 22k included glossy brochures, 3d mock ups, a local area study, material pallets for the planning application as well as a "liason" officer to manage planning. Technical drawings for building regs and a folder of technical specs for the build. It also included a number of hours for revisions/support once the build starts, but no direct involvement in the build.

 

If you want to have a drawing of every nail, wire and socket 22k is great.

If you are happy to make your own decisions on the go.  it is a lot of money on something that could become quite rigid.

 

From what you have described you should be able to find a structural engineer, a technician and submit to building regs for less than 4k, 15k is nuts and will probably take a lot longer.

 

 

 

 

[ETC]

“Look for a recommended Architectural technician (Not Architect) that works closely with a structural engineer.”

 

@Scobbyrex….Why not an architect?…….

[IanR]

+1 for an Architectural Technician, not an Architect.

 

Rates are lower, and quite often at this stage you are just paying a premium for the Architect to instruct a Technician in their office.

 

If you are trying to achieve better than Building Regs insulation, airtightness and cold bridging, then pick someone with that experience. (You may have to select an Architect for this one as there is less to choose from). 

 

If you are in any doubt on the foul drainage, get the SE or a specific drainage Engineer to design the foul and surface water drainage.

 

Get talking to who ever is supplying your windows and doors to agree how they interface to your structure and floor.

 

I wouldn't wait to do the MVHR, I'd get this designed while you are at the drawing stage of the structure, it could save a lot of large holes needing to be drilled.

Nor would I wait to know where the large plumbing items are going, SE may need to know where the cylinder is and how large. UFH Manifolds and loops should also be known before you finalise your floor.

 

There's a lot of work to do - £4K + SE is reasonable.

 

 

Edited July 13, 2021 by IanR

[Nick Laslett]

On 06/07/2021 at 15:24, Babak said:

Hello

 

I have the planning permission and am planning to proceed to the build phase. My own architect cannot help the end of August at the earliest and I would like to book the builders ASAP given the lead times. I plan to use ICF for walls and a related product from the same guys for the roof structure (Thermohouse). I also know the material types to be used elsewhere (eg type of render, first floor posi joist depth, opening dimensions, etc.

 

#snip.

 

Thank you!

 

 

 

Hello, we are half way through our build with Thermohouse. We used their structural engineer and their team for the build. Our architect did the internal soil vent pipe/waste water design in conjunction with a drainage design engineer for the external drainage and rainwater. We are not on main drainage and needed a package sewage treatment plant. 

[saveasteading]

Many Chartered Architects are good value and know what they are doing. Likewise technicians.

Many Chartered Architect's will not be expert with normal domestic houses. Likewise technicians.

 

Yes, an Architect has to study for 7 years further education before proper earnings, but they don't necessarily charge you extra for their lean years or the skills learnt.

 

I suggest rule neither out.

Even where an Architect's practice sounds like a big setup, (The Smith, Brown and Jones Partnership) they often work as individuals, and don't have big overheads.

[oldkettle]

1 hour ago, Nick Laslett said:

we are half way through our build with Thermohouse. We used their structural engineer and their team for the build

If you don't mind me asking, what is your foundation / floor slab? I was a bit disappointed they don't have a standard insulated raft offering. 

[Gus Potter]

On 06/07/2021 at 15:24, Babak said:

Finally, one of my planning conditions is not to commence development above the slab level before external material has been approved. Am I right in presuming that I can still demolish?

 

Thank you!

 

 

 

Hello Babak.

 

Please be very careful here. Unfortunately I have seen cases where folk have been a bit too hasty with the demolition and one case where the planners prevented them from rebuilding. There was some other history but it can be that serious!

 

It looks like you have a fair idea of what you want and have a "design" in mind. Also, it looks like you have already put a fair amount of thought into build method, servicing it and so on.

 

What about contacting some SE's? As you are proposing ICF for part of it there are a good few that have a grasp of the fundamentals of this and from their point of view it's often more interesting than just doing the day to day stuff, so they may think.. yes that looks like a project I would like to do. I'll also do the "Architectural side2 and building approval side" as the Client already has a good grasp of what they want and, as I'm drawing it up I'll do the structural calcs as I go along.. it's a very efficient way of doing it!

 

In summary there are a few SE's who also do the whole package, calcs, drawings, a bit of the Architectural design and building approval so don't rule this option out.

 

Even if you don't go this full route there are SE's who will give you a good few pointers and offer their contact base to you. There is a perception that for design you have to first get an Architect.. then an SE.. then a contractor. But all these folk often work and collaborate, learn from each other anyway. So don't rule out approaching an SE, explain what you need. You may get a pleasant surprise as they may say.. well I can do most of it but I know an Architect that can say deal with the parts that are outwith my expertise.

 

 

 

[Nick Laslett]

14 hours ago, oldkettle said:

If you don't mind me asking, what is your foundation / floor slab? I was a bit disappointed they don't have a standard insulated raft offering. 

 

I went with the Kore Insulated Foundations. I used Tanner for the foundation design and he works closely with Kore.

[Scoobyrex]

On 13/07/2021 at 14:47, ETC said:

“Look for a recommended Architectural technician (Not Architect) that works closely with a structural engineer.”

 

@Scobbyrex….Why not an architect?…….

 

Availability and cost.  To take the design you have and get it ready for the structural engineer to continue doesnt need an Architect.  Find the structural engineer you want to use (most likely based on availability) and ask for a recommendation for who they would advise you to use to get the material matters drawings ready for them.

 

They will recommend someone who they work well with over and over again.  

[IanMcP]

On 14/07/2021 at 09:55, Nick Laslett said:

 

I went with the Kore Insulated Foundations. I used Tanner for the foundation design and he works closely with Kore.

keen to know more about your build and how it went with kore 

[Andrea Long]

thanks everyone some good helpful advice in the thread

[Nick Laslett]

On 26/12/2021 at 21:01, IanMcP said:

keen to know more about your build and how it went with kore 

I ordered direct from Kore and asked them to recommend an installer in the UK. At the time there was a minor delivery issue with the Customs Agent and my EORI number. Kore used the drawings from Tanner to produce the exact EPS blocks and provided details on assembly. The blocks took two days to assemble. The previous 2 weeks the groundworkers had prepared the plot up to the sand level as detailed by Tanner. There was a further 4 days for putting in rebar mesh and laying underfloor heating. Then a final day for the concrete pour. I organised the concrete supply, I order the rebar as per Tanner’s spec. The installer power floated the concrete. I was very happy with the whole process. Observations; unloading the EPS delivery is a major task. This was the only lorry driver during the build so far that was unable to get their lorry on the site, we used a dumper to ferry the blocks from the lorry. There were five of us doing the unloading, took at least 1 hour. Don’t throw away the EPS used for packing the foundations, this has been very useful for the rest of the build for making temporary work tables, platforms for timber, temporary window cover, many uses. I will be using weatherkem cement board for finish the perimeter of the foundation. Lots of posts here on this topic. The installer and the ground works did a great job and there was just 1 corner with a 5mm height variance, this was caused by the groundworkers. The ICF builder shaved the EPS here to make it level.