Architect costs

[Nickfromwales]

11 hours ago, ETC said:

Who in their right mind designs structural support over a drain?🙈……the extension isn’t really worth doing!

Now I’ve seen this, the architect is appearing to be another self-perpetuating over inflator, as this is just soooooo simple and straightforward.

 

Local, reputable builder will do this with one eye closed.
 

M&E??? “Where would you like the 3x switches and 3x sockets, sir?”  🤦‍♂️. 
 

Get a set of construction drawings, A3 for your reference, and laminated A2 for site / contractors use, and sit with the builder to go through every stitch of the detail (when vetting builders) and see what they spot, comment on, and how engaged they are.
 

Then, when you’ve decided on ‘the one’ you need to go and see their previous work, in person, and possibly align so its the right time of day to speak to them face to face to see if it all went well etc. 

[Mr Punter]

12 hours ago, ETC said:

Who in their right mind designs structural support over a drain?🙈……the extension isn’t really worth doing!

+1

The extension only gains about 4m2 and you have to mess with joining ceilings and floors, plus insulation continuity.  Nightmare of a job.

[saveasteading]

Presumably all bills are paid so you have invested deeply. I can see that this very small extra floor could greatly improve the upstairs room.

 

The SE sounds OK. Don't burn bridges but ask for all the work so far and you will " come back to them".

Did the architect select them? So may be close, which isn't bad in itself.

 

Ask for all thearchitects's work too, incl any correspondence. Same excuse.. it's on hold but I'll have what I've paid for.  I fear it will be surprisingly little.

Especially ask for all enquiries and responses re building over the drainage..... I do think that should have been concluded before planning. Talk to the architect ASAP.

 

Then find that builder. The cheapest is unlikely to be best value but you never know. £20k + vat, off the top of my head, to include bco , and that should include all except an SE visit.

 

But do nothing until the drain issue is permitted.

[torre]

This is going to be very expensive to build to turn a smallish bedroom into a bigger one and add a porch - if you ignore how much you've already spent, are you 100% this is the best way to improve your house and meet your needs?

 

Sunk cost is painful but not a good reason to keep spending more money. I appreciate I'm not in your shoes but I struggle to see this being worth the cost and disruption

[Spinny]

2 hours ago, Nickfromwales said:

Get a set of construction drawings, A3 for your reference, and laminated A2 for site / contractors use, and sit with the builder to go through every stitch of the detail (when vetting builders) and see what they spot, comment on, and how engaged they are.
 

Then, when you’ve decided on ‘the one’ you need to go and see their previous work, in person, and possibly align so its the right time of day to speak to them face to face to see if it all went well etc. 

Spot on as usual.

 

There has to be someone on a build that is good with detail and can discuss detail. I mean 'detail' can actually just mean having actually looked at the drawings at all !

 

When seeing previous work and customers definitely go prepared with list of specific questions and willing to dig down a bit. A quick look around and general chit chat with Mrs Smith isn't going to shed much light. Can they give you an example of an issue that came up and how it got resolved ? Did they have effective review meetings ? Was the actual builder on site - every day - once a week - once a month ? Did people turn up ? Did anything get redone or corrected ? Costs ? Schedule ? If the customer doesn't know then chances are they can't really give any insight into the builders competence. Perhaps the foundations are made of cream cheese - Mrs Smith wouldn't know.

[Spinny]

8 minutes ago, torre said:

are you 100% this is the best way to improve your house and meet your needs?

One approach is to look at what the cost/sqm is going to be. Compare with the cost/sqm of similar property on RightMove. Think about long term needs/plan. Yes moving costs and stress are high, and there can be reasons to 'build at a paper loss' if other factors come in. But you should know what your economic justification is.

[ProDave]

Can this not be done under a building notice ?  Is that still allowed?  30 years ago we built a much larger side extension under a building notice with a very good builder and it was a cost effective way to nearly double the size of the house.

[Nestor]

4 hours ago, torre said:

but I struggle to see this being worth the cost and disruption

I agree with @torre

For such a modest change to the property I could not justify the cost and feel the professional services fee is already disproportionate to the scale of the project.

If you still plan to move forward at least build a proper enclosed lobby, new front door, etc instead of just a porch.

[Redbeard]

AI says that Sheffield City Council says: "You can only use this for minor domestic jobs. You must use a Full Plans application instead if your project is near a shared public sewer or affects a commercial building. [1, 2]". Maybe it's the drain.

[Redbeard]

Sorry, my previous post relates to @ProDave's sugg'n of a Bldg Notice. I too remember when you could do major works, or even a new-bld IIRC, on BN.

[Gabriel the Toad]

Hi, thanks for all the discussion so far! It's giving me lots to think about! 

 

When it comes to points about the small size of the extension - the idea is not to increase the value of the house, as I have no plans to sell, and definitely don't want to move. Although turning a poky single bedroom into a reasonably-sized double might increase the value, actually I want a 'hobby room' which is ideally long and narrow (I intend to build a model railway around it!), and when a figure of £30k was mentioned I decided that was acceptable to me. 

 

Any other kind of extension would be difficult - house is link-detached so cannot go out sideways. A loft conversion would be possible (some others in the road have done this) but the height of the roof ridge is very low - and I'm 6'1". Extending out backwards might be possible, but the garden is small and a first floor extension there would definitely annoy the neighbours. I did think of 'filling in' the base of the new extension to make a bigger downstairs hallway, but wouldn't find this space very useful, and it would also block some light and views from the living room window. Also the intention is to match the appearance of my neighbour's extension.

 

Re the course of the sewer - this runs along the front of a group of 4 link-detached houses, then into the road. My neighbour's extension did not have to worry about this, as they are on the end of the row, so the sewer commences at their manhole, it doesn't go under their posts. 

 

So looking at the Southern Water website, it looks as though I could apply for "build over" permission myself, and pay the £771.60. I'm not sure if I have all the documents they detail on this page though... will have to go through what I have... also unsure what happens if they refuse permission; is the money lost and I have to get revised plans, with the posts moved, and start again?

 

 

[saveasteading]

59 minutes ago, Gabriel the Toad said:

pay the £771.60

ouch.   The SE should be able to advise the likelihood of agreement.

The purpose is that your design should not apply any weight at all to the pipe or its surounds.

Also to allow the pipe to be worked on or replaced without added dificulty.

I expect the solution to be to excavate on both sides  to below the pipe bedding, and pour concrete bases to above the drain level, and ensure gravel is over the top.

Then a layer of polystyrene to ensure no loading from above, and then a bridge of concrete with reinforcement, up to ground level or wherever the post goes.

That's all straight-forward, other than being old-fashioned spade work.

 

But I think the next stage is still to get the information you have paid for, and find a builder or  two. 

A good one will give an approximate cost based on gut feeling, or a think about how long it will take his 2 or 3 guys. (labour  x 3 will be about the cost.)

And if they say £50k or more  I assume you can then make your decision easily.

 

[Gus Potter]

On 06/07/2026 at 18:18, Gabriel the Toad said:

I've posted a couple of extracts below.

Would this help?

 

 

 

It looks like you might have space to move the public sewer outwith the zone of influence of the new foundation? I'm assuming the direction of flow runs left to right on the drawing. If not then just reverse the diagram. 

 

For reference a private drain is a drain that serves only one house, a public sewer serves more than one house and often this asset belongs to the water board. As others have said you should determine,if you need build over permission for this, you will need permission to move the sewer,  build over or near to it. The notation R/E indicates a rodding point.

 

Best to do it right to avoid later potentially horrendous complications. 

 

 

[ProDave]

Why position the posts directly above the pipe?

 

Move them both towards the house a bit so they are not over the pipe, dig their foundations below the pipe and build up from that to support them without imposing weight on the pipe.

 

Then a semi cantilever frame to support the weight of the extension on the posts now closer to the house.