Building Extension

[Basecoat]

Using trench foundation blocks means I only have to lay strip concrete to thickness of 200mm. Do I have to put reinforcing bars in.

How wide are your footings going to be??

Hi "static"

On the plans I have submitted for building regs Foundations are:
Concrete strip foundations 600mm wide x 225 high minimum depth 900mm.

What is the best way to achieve this.

 

[Static]

Make the footing 300mm deep and youll prob not need any reinforcement, what kind of soil are you bearing into at that depth?

 

[joe-90]

Your building inspector will want to look at your trench and will tell you if they are deep enough (looking for stable ground). Ask him about tying in the foundations. It often causes the main house to crack if the extension moves.
There are ways to join it that allow for movement.


joe

 

[Basecoat]

Make the footing 300mm deep and youll prob not need any reinforcement, what kind of soil are you bearing into at that depth?

Hi "static"

Last year digging foundations for retainer wall I hit clay. An awful stuff to dig and shift when wet. House is some 25meters away from retainer wall therefore I assume there is clay.

I am not sure if I have been given correct info that with clay you don't have to go too deep. Guys point to right direction.

 

[Basecoat]

Your building inspector will want to look at your trench and will tell you if they are deep enough (looking for stable ground). Ask him about tying in the foundations. It often causes the main house to crack if the extension moves.
There are ways to join it that allow for movement.


joe

Hi "joe"
Thanks Joe another point taken. I have noted in my book for reference.
You are absolutely right I recently saw original wall cracked but the extension wall wasn't. Another point why don't they "tie" walls like they used to do in years gone by. It was hard work but attached walls were solid.

 

[Static]

Clay is fine, just make sure its undisturbed clay solid. You should be taking your new footings down to a the same depth your existing house footings or 1m which ever is more. Any trees near the new extension?

Your best course of action is to dig a small trial pit down side of house to existing footing level (located around place where you intend to put your new footing). See what size/depth the footings (take photos).

 

[Basecoat]

Clay is fine, just make sure its undisturbed clay solid. You should be taking your new footings down to a the same depth your existing house footings or 1m which ever is more. Any trees near the new extension?

Your best course of action is to dig a small trial pit down side of house to existing footing level (located around place where you intend to put your new footing). See what size/depth the footings (take photos).

Hi "static"

That is great. A grand idea to see what the exhisting foundations are like. Also avoid guess work which can mean delays and additional cost. Went to tool hire shops for pricing. One independant shop cheaper than HSS and local.

Bit by bit it is all coming together and making sense. Please continue feeding info. I am sure there will others like myself benefitting.

I am going to approach my neighbour for his approval to use party wall. The council planning insist better to obtain written consent rather than verbal. I plan to do just that. Neighbour is on good terms therefore no problem there. I will dig a trail pit this weekend.

 

[Static]

ACK!
What are you doing to the party wall, if your digging around over or anywhere near youll need to give him written notice and get written concent to carry out the works.
You can get into deep deep mucky stuff if you dont. Ive known people to demand (and getting) upto £20000 just to allow a crane to oversail their property for 3 months.
It can end up cheaper to get a party wall surveyor in to deal with all the concents and get agreements etc or you may end up paying alot of cash in the end of the day.

 

[Basecoat]

ACK!
What are you doing to the party wall, if your digging around over or anywhere near youll need to give him written notice and get written concent to carry out the works.
You can get into deep deep mucky stuff if you dont. Ive known people to demand (and getting) upto £20000 just to allow a crane to oversail their property for 3 months.
It can end up cheaper to get a party wall surveyor in to deal with all the concents and get agreements etc or you may end up paying alot of cash in the end of the day.

Hi "Static" Jack

Thank you jack for making me aware of this often hidden issue. I shall speak to neighbour this weekend. I will get written consent before I attempt any digging. I consulted him before drawing the plans. When I completed my sketches I consulted him. He had no objections but people can change as you have rightly pointed.

The party wall in question is 2meters high x 1450 wide with slanted roof.

 

[Static]

The "Party Wall etc Act 1996" applies throughout England and Wales.
The Act covers:

1. New Building works at or astride the boundary between two properties.

2. Structural work affecting an existing shared/party wall, including repairs, alterations, extending or reducing the wall, cutting into the wall and underpinning.

3. Excavating, or constructing foundations within three metres of a neighbour's building where the new foundations will go deeper than the neighbour's.

4. Excavating, or constructing foundations within six metres of a neighbour's building where the new foundations will cut a line drawn downwards at 45 degrees from the bottom of the neighbour's foundations.

If you are the owner proposing to have the works carried out, you must identify whether the works are governed by the Act. If so, you must serve statutory notice (one or two months depending upon which part of the building is affected) on the adjoining owners and get agreement to the building programme, before you start.

If your neighbours do not agree in writing, the preferred solution would be to appoint one surveyor to draw up a Party Wall Award. This surveyor should be independent and should not be involved in the design or specification of the works. If you cannot agree a surveyor, then each side should appoint their own surveyor. The Party Wall Award will set out what can and cannot be done in accordance with the Act.

If you are the adjoining owner and receive a party wall notice, you may agree to the proposed works if you are entirely happy that there will be no damage or consequences to your property. Otherwise, if you do not agree or if you ignore the notice, then you must agree to a single surveyor being appointed, or appoint your own. If your do neither then a surveyor should be appointed for you by the owner carrying out the works. Where a surveyor is appointed, a schedule of condition of your property will be prepared (in case any damage is caused) and a Party Wall Award will be prepared.

The owner who is carrying out the works normally pays the fees of the surveyors. Fees for such services vary according to the nature and extent of the works.

You should give at least 1 months notice on any building works effecting the party wall. But as you say your in good relations with your neighbour so getting written concent shouldnt be a prob.

 

[Basecoat]

The "Party Wall etc Act 1996" applies throughout England and Wales.
The Act covers:

1. New Building works at or astride the boundary between two properties.

2. Structural work affecting an existing shared/party wall, including repairs, alterations, extending or reducing the wall, cutting into the wall and underpinning.

3. Excavating, or constructing foundations within three metres of a neighbour's building where the new foundations will go deeper than the neighbour's.

4. Excavating, or constructing foundations within six metres of a neighbour's building where the new foundations will cut a line drawn downwards at 45 degrees from the bottom of the neighbour's foundations.

If you are the owner proposing to have the works carried out, you must identify whether the works are governed by the Act. If so, you must serve statutory notice (one or two months depending upon which part of the building is affected) on the adjoining owners and get agreement to the building programme, before you start.

If your neighbours do not agree in writing, the preferred solution would be to appoint one surveyor to draw up a Party Wall Award. This surveyor should be independent and should not be involved in the design or specification of the works. If you cannot agree a surveyor, then each side should appoint their own surveyor. The Party Wall Award will set out what can and cannot be done in accordance with the Act.

If you are the adjoining owner and receive a party wall notice, you may agree to the proposed works if you are entirely happy that there will be no damage or consequences to your property. Otherwise, if you do not agree or if you ignore the notice, then you must agree to a single surveyor being appointed, or appoint your own. If your do neither then a surveyor should be appointed for you by the owner carrying out the works. Where a surveyor is appointed, a schedule of condition of your property will be prepared (in case any damage is caused) and a Party Wall Award will be prepared.

The owner who is carrying out the works normally pays the fees of the surveyors. Fees for such services vary according to the nature and extent of the works.

You should give at least 1 months notice on any building works effecting the party wall. But as you say your in good relations with your neighbour so getting written concent shouldnt be a prob.

Hi "Static"

Many thanks. I will find out tomorrow. I have a drafted a letter of consent hopefully he will sign it. He will talk with his son before he does it though. A bit of a "knowall" type. I am going to take my time and proceed with precaution ensuring each step is proper thus avoiding pitfalls.

 

[Static]

Nice to hear..
I'm sure it will be fine..

 

[Basecoat]

Nice to hear..
I'm sure it will be fine..

Hi Static"

Spoke to neighbour yesterday. He said no problem but that is not enough I need to get the permission in writing. His son is going to put it in writing hopefully in the next couple of days.

 

[stevie-b]

best advice i can think of is to plan everything.
I am finishing a two storey extension to a terraced house.
Its been great, only one hickup so far. I had placed doors were the upstairs windows were, creating a stud partition wall to frame the doors.
I forgot to insulate the gap so there is no sound privacy now! I threw away loads of bits of insulation as well.
I dug the foundations deep which seemed to impress the inspector who is used to pushing self builders to do the job properly.

 

[Basecoat]

best advice i can think of is to plan everything.
I am finishing a two storey extension to a terraced house.
Its been great, only one hickup so far. I had placed doors were the upstairs windows were, creating a stud partition wall to frame the doors.
I forgot to insulate the gap so there is no sound privacy now! I threw away loads of bits of insulation as well.
I dug the foundations deep which seemed to impress the inspector who is used to pushing self builders to do the job properly.

Hi "Stevie-b"

I well come your advice as well. This is helping me compile a quick reference of do's and don'ts. Minor errors can be corrected easily but major ones can be costly both in money and in time loss.

I am impressed about your deep foundations. This was suggested to me by a retired builder other week. He said the building stands on sound foundations. Bad/weak foundations is a recipe for disaster. Get your foundations right there is little to go wrong then unless you get into careless mode.