Extension build - what do I need to know?

VW 1

Hi All, have tried a forum search but the function is rubbish on mobile.

Currently looking at purchasing a property in Dublin 9 which is a standard 3 bed semi D, with no extension and room to build on at the back/side.

Provisional thinking on this is to build an extension which will go back from the main house and also wrap around the side of the house.

Firstly, to do this, is there planning permission required in order to proceed with the building work?

Second query would be in relation to costs, roughly how much per m2 would be a reasonable estimate to bring to a builders finish? Can more reasonably estimate the costs of finishing etc from that point.

Is there anything else I need to consider?

Thanks.

Gumbo

VW 1 wrote: »

Hi All, have tried a forum search but the function is rubbish on mobile.

Currently looking at purchasing a property in Dublin 9 which is a standard 3 bed semi D, with no extension and room to build on at the back/side.

Provisional thinking on this is to build an extension which will go back from the main house and also wrap around the side of the house.

Firstly, to do this, is there planning permission required in order to proceed with the building work?

Second query would be in relation to costs, roughly how much per m2 would be a reasonable estimate to bring to a builders finish? Can more reasonably estimate the costs of finishing etc from that point.

Is there anything else I need to consider?

Thanks.

Planning permission required based on what you’ve posted.
Budget €2k per square meter to roughly get a total floor area you want.
Then get quotes based on what is granted through the planning process.

cruizer101

Just a heads up that there are new building regs coming in that mean if you are making changes to a house that require plannign permission you also have to upgrade the rest of the house the have an overall BER of B2 which depending on the house could add significant cost.
https://www.irishtimes.com/news/politics/new-energy-rules-for-home-renovations-and-extensions-1.4031816

sydthebeat

cruizer101 wrote: »

Just a heads up that there are new building regs coming in that mean if you are making changes to a house that require plannign permission you also have to upgrade the rest of the house the have an overall BER of B2 which depending on the house could add significant cost.
https://www.irishtimes.com/news/politics/new-energy-rules-for-home-renovations-and-extensions-1.4031816

The statement in bold is incorrect

i dont blame you though, the reporting in the proposed changes has been nothing short of ill informed ignorant scare mongering.

VW 1

Great, thanks. After I posted last night I found the costs and planning section, and found more information.

Is the planning requirement due to building at the side? Or because what I described is potentially more than 40m2? Is the planning process a time consuming and costly process, or is it relatively straightforward?

Basically, we are trying to determine how much we can afford to pay for the house and leave adequate cash for doing works required etc, so appreciate the time spent responding.

blindside88

Just to play devils advocate. Would you be happy with the house if you were not able to build the extension. Planning permission is not guaranteed to be granted and you could end up with a house that is too small and end up incurring further costs to sell.

sydthebeat

VW 1 wrote: »

Great, thanks. After I posted last night I found the costs and planning section, and found more information.

Is the planning requirement due to building at the side? Or because what I described is potentially more than 40m2? Is the planning process a time consuming and costly process, or is it relatively straightforward?

Basically, we are trying to determine how much we can afford to pay for the house and leave adequate cash for doing works required etc, so appreciate the time spent responding.

once you go beyond the side of your house, you require planning permission, irrespective of size

cruizer101

sydthebeat wrote: »

The statement in bold is incorrect

i dont blame you though, the reporting in the proposed changes has been nothing short of ill informed ignorant scare mongering.

Any link to actual requirements. I did hear somewhere else something along the lines of if more than 25% of the surface of the building is changing than need to upgrade BER.
Tried looking into it a bit further but couldn't find anything.
What ever it is, it is likely something that people buying secondhand houses with plans to extend need to at least be aware of.

sydthebeat

cruizer101 wrote: »

Any link to actual requirements. I did hear somewhere else something along the lines of if more than 25% of the surface of the building is changing than need to upgrade BER.
Tried looking into it a bit further but couldn't find anything.
What ever it is, it is likely something that people buying secondhand houses with plans to extend need to at least be aware of.

https://www.seai.ie/publications/NZEB-in-Domestic-Buildings.pdf

This is a decent introduction document.

"major renovations" from page 14 onwards

VW 1

blindside88 wrote: »

Just to play devils advocate. Would you be happy with the house if you were not able to build the extension. Planning permission is not guaranteed to be granted and you could end up with a house that is too small and end up incurring further costs to sell.

In the situation where we couldn't get planning permission, putting a regular extension straight out the back up to circa 40m2 would definitely meet our needs, the side building would have been to include a utility room and downstairs bathroom, and possibly a second sitting room. I'm sure 40m2 out the back would easily accommodate our needs, just in a different layout to our original plans.

Thanks for clarifying also, Sydthebeat. Nice username, I'm presuming after Syd, from the internet?

Gumbo

cruizer101 wrote: »

Any link to actual requirements. I did hear somewhere else something along the lines of if more than 25% of the surface of the building is changing than need to upgrade BER.
Tried looking into it a bit further but couldn't find anything.
What ever it is, it is likely something that people buying secondhand houses with plans to extend need to at least be aware of.

From the actual Technical Guidance Documents : https://www.housing.gov.ie/sites/default/files/publications/files/tgd_l_dwellings_2019.pdf

TRANSITIONAL ARRANGEMENTS

In general, this document applies to works, or dwellings in which a material alteration or change of use or major renovation
commences or takes place, as the case may be, on or after 1st November 2019. Insofar as the guidance contained therein relates to
dwellings, Technical Guidance Document L - Conservation of Fuel and Energy – Dwellings 2011 (Amended 2017) ceases to have effect
from 31st October 2019. However, the foregoing document may continue to be used
in the case of dwellings: - where the works, material alteration, change of use or major renovation commences or takes place, as the case
may be, on or before 31st October 2019,

or

- where:
a) planning approval or permission has been applied for on or before 31st October 2019 and substantial work has been completed by 31st October 2020 or;
b) a notice pursuant to the provisions of Part 8 of the Planning and Development Regulations 2001 (S.I. No. 600 of 2001) has been published on or before 31st
October 2019 and where substantial work has been completed by 31st October 2020.
“Substantial work has been completed” means that the structure of the external walls
of the dwelling has been erected

Existing Dwellings

0.1.3.1 This amendment applies to all works to existing dwellings that are covered by the requirements of the Building Regulations,
including extensions, material alterations, material changes of use, major renovation and the replacement of external doors,
windows and roof lights. In carrying out this work, the aim should be to limit energy requirements for the operation of the dwelling
and associated CO2 emissions as far as is practicable as required by Regulation L1.

The key issues to be addressed are:

(a) Fabric insulation: providing reasonable levels of fabric insulation in all new construction, including the limitation of
thermal bridging including, where provided, replacement windows and doors. Guidance is given in sub-sections
2.1.2 and 2.1.3;

(b) Air tightness: limiting air infiltration through the newly constructed elements as far as is practicable. Guidance is
given in sub-section 2.1.4;

(c) Heat Generator: providing an efficient heat generator as set out in sub-section 2.2.2

(d) Building Services Controls: where new space and/or water heating services are provided, controlling, as appropriate, the
demand for, and output of these space heating and hot water services. Guidance on appropriate measures is
given in sub-section 2.2.3; and

(e) Insulation of pipes, ducts and vessels: limiting the heat loss from pipes, ducts and vessels used for the transport or
storage of heated water or air, as set out in sub-section 2.2.4.

(f) When a dwelling undergoes major renovation, the energy performance of the whole dwelling should be improved to
cost optimal level in so far as this is technically, functionally and economically
feasible. Guidance is given in section
2.3

VW 1

Just one more question (hopefully). Would you guys recommend engaging an architect for a project, and is it essential? What are the advantages of going with one as opposed to letting a builder project manage it, and what type of cost as a percentage of the total spend is it likely to be?

jmBuildExt

The architect will be unllikely to fully "manage" your build.
In general...
He will do design, and construction drawings, send out and manage tenders. After a main contractor is selected, the arch will do periodic checks and write certs to say how much the main contractor should be paid for each stage, basically comment on completeness. Generally speaking, he wont be there every day or even every week. You will need an engineer to sign off on the foundations/steel work etc (whether you have an architect or not)

As a rule of thumb you will pay the arch about 10% of the construction costs (he may not set it out like that, but that's usually what it will be)

sydthebeat

VW 1 wrote: »

Thanks for clarifying also, Sydthebeat. Nice username, I'm presuming after Syd, from the internet?

not sure whats thats in reference to.....

but i got my name from this guy:

https://www.thisdayinmusic.com/stairway-to-heaven/syd-barrett/

VW 1

sydthebeat wrote: »

VW 1 wrote: »

Thanks for clarifying also, Sydthebeat. Nice username, I'm presuming after Syd, from the internet?

not sure whats thats in reference to.....

but i got my name from this guy:

https://www.thisdayinmusic.com/stairway-to-heaven/syd-barrett/

Ah, there's a female rapper from a group called The Internet and she goes by Syd the Beat sometimes!