New erection of attic. Advise needed.

[sduckie 0]

I have a small inter-terrace with land size of about 82sqm which is currently 2 storey high and have an empty attic level. Planning to open up the attic level to make in greater usable space by doing an A&A to erect the roof attic.

The house is in original condition, built around the 1960s. So thorough renovations on all levels are required.

I had approached about 6 builders for quotations and the quotes had a wide range of difference. Quoting from 250k to a whopping 600k for that A&A.

The higher ends quote had very expensive carpentry works. Some even had kitchen carpentry that cost 30k. After seeing the price range difference, I feel like a walking carrot...

 

Any advise out there or people with experience in small size inter terrace attic extension? Want to know a realistic price range that I should accept.

 

Also looking for experience, honest and sincere builders and PE recommendations. Going for prudent works.

 

 

 

[snoozee 98]

suggest you find an architect and have a PE look at your existing building plans first and advise you on whether your planned additions can or cannot be done. 

250k in today's context is highly impossible. 600k may seem high but could be reasonable depending on your scope of work.

30k for carpentry work isn't that expensive. honestly, today even if you have money, you may not be able to find carpenters to take your job. the construction labour market is very bad due to the border closure measures so if you want work done, be prepared to pay for it.

[3Cube 9]

When you say "empty attic level", is there currently a staircase from the 2nd storey going up to the "attic"?

If there is no staircase, then this is a RC roof. Which means your foundation caters to only 2 storey. Addition of the attic & a new roof cannot be done "Lego" style.

[sduckie 0]

15 hours ago, 3Cube said:

When you say "empty attic level", is there currently a staircase from the 2nd storey going up to the "attic"?

If there is no staircase, then this is a RC roof. Which means your foundation caters to only 2 storey. Addition of the attic & a new roof cannot be done "Lego" style.

Thanks for the advise. We were told by some after their assessment that slab extension can be done for the roof. Do you have any experience on it? Is slab extension counted as Lego? 

[sduckie 0]

15 hours ago, snoozee said:

suggest you find an architect and have a PE look at your existing building plans first and advise you on whether your planned additions can or cannot be done. 

250k in today's context is highly impossible. 600k may seem high but could be reasonable depending on your scope of work.

30k for carpentry work isn't that expensive. honestly, today even if you have money, you may not be able to find carpenters to take your job. the construction labour market is very bad due to the border closure measures so if you want work done, be prepared to pay for it.

Yeah. Almost everyone couldn't promise us a confirmed work completion date. Seems like it's better to delay the works until we get more certainty. A stalled construction is rather costly right...

[snoozee 98]

1 hour ago, AlvinQ said:

Yeah. Almost everyone couldn't promise us a confirmed work completion date. Seems like it's better to delay the works until we get more certainty. A stalled construction is rather costly right...

the situation is still very fluid even 1 year plus on since the start of the pandemic. if there's no urgent need to start works now, better to delay until at least the construction labour market improves. construction delays are costly especially if you are planning to take loan to finance it. the construction loan interest rate is much higher than a mortgage loan rate and you will continue to pay the high interest rate until you get your TOP/CSC. if work has to be stopped on site due to whatever reasons, the bank doesn't stop charging you interest.

do you have your original build plans from BCA already? for a house built in 1960s, i doubt there is a RC slab cast for an attic. my own house which was build in late 1950s does not come with a RC slab for attic. one thing to note for old houses is the existence of asbestos. asbestos is a cancer causing material which was widely used in construction before is was banned in the 1980s. so if your house does has asbestos, you will need to have them removed for safety reasons and this needs to be done by a licensed contractor.

[3Cube 9]

4 hours ago, AlvinQ said:

Thanks for the advise. We were told by some after their assessment that slab extension can be done for the roof. Do you have any experience on it? Is slab extension counted as Lego? 

I think you grossly misunderstand the concept.

My analogy of "Lego" is base on layman understanding / concept that extra element such as added floor, roof, etc can be simple stack up without any, strengthening or improvement or addtions to FOUNDATION.

This is what i mean by my analogy "Lego" & this concept is EXTREMELY LETHAL, HIGHLY DANGEROUS & SHOULD NEVER be applied to buildings.

Think New World Hotel & you'll get a clearer picture.

The following are my best educated assumption based on my personal past 25+ years of building construction experience. Also I have not seen your property & the relevant structural plans (which likely to have a records with BCA which the legal owner can purchase).

This will be my assumption of the worse case scenario.

In your case, an inter-terrace means left & right wall is shared with your neighbors. No side setback.

You also mention this was constructed & completed in 1960s.

Hence, high probability that minimal footing is provided between the shared left & right wall. The only thing holding up your building (ie: handling & distributing the loads down to the soil / earth / ground) is the strip footing along the left & right shared walls. This was the normal design practice way back then.

Whatever slab extension or added floor can be done to the building. But emphasis must be on the foundation improvement.

To put it bluntly, your current condition will not be able to take up the extra load.

Now you may think of saving construction cost by simple retain existing building, hack the 1st storey partially to install piles or footing, patch up the hacked portion of 1st storey & just add columns.

This will be extremely costly & NOT economically effective.

Why?

To do this you must consider the machinery involved & I assume you have a low headroom to move in the bulky machinery. likely you'll need to remove part of 2nd storey for the machine to even move in. So you'll end up with a high rate (ie: $$ per square feet) Also not forgetting to advice you, partial hacking or spot demolition is higher cost than total demolition of building. Think of work flow involved (everything from hacking to removal of debris to working space to patching up to match surrounding) & you should understand. This on top of the issue regarding duration.

Having said all that. You need to also know any addition of floor area (ie: GFA, building height, etc) must be submitted & subjected to Authorities' (ie: URA, BCA, etc) approval.

Edited June 15, 2021 by 3Cube
spelling check & added content