Pre Construction of a landed house - Considerations and Questions

[AWS 6]

Not sure if it’s true, I have heard from my builder that soil test results are now lodged with BCA/SLA (I am not sure specifically which agency) and if your immediate neighbour has just done rebuild recently, you can use his soil test result on request from that specific agency. Maybe the result can be used as long as it’s not too far away. I may be wrong but there will be cost savings if it’s true. 

[leechaorui 2]

12 hours ago, AWS said:

Not sure if it’s true, I have heard from my builder that soil test results are now lodged with BCA/SLA (I am not sure specifically which agency) and if your immediate neighbour has just done rebuild recently, you can use his soil test result on request from that specific agency. Maybe the result can be used as long as it’s not too far away. I may be wrong but there will be cost savings if it’s true. 

Thanks.  The length of my house is about 43m and I am about 20m away from my neighbour's house.  I heard that the soil test results can be used if it is within 50m radius.

I have just started on soil test and will take a few more days to complete.  Will be starting on topography survey in early November.  All these works have been commisioned last week.

Edited October 24 by leechaorui

[snoozee 98]

15 hours ago, leechaorui said:

For the higher floor balcony fences, do you use galvanised steel or some other materials?  Prefer not to use glass as it is unfriendly to birds which may crashed onto the glass and perish.  There are lots of song birds that come to my garden and I would like to make it a safe environment for them.

For stairways guard, do you use grills or glass?  Both seems like quite a lot of work to clean and glass got the added risk of breakage.  What other options are available

For home lift, which is a prefered brand.  Lift should be able to take at least 4 pax and wheelchair accessible.  What the things to know when buying and installing a lift including lift shaft? 

my railings are all using painted mild steel. birds don't die so easily when they crash into things. I've had birds flying into my glass doors and they just bounce off and fly away.

the railings are meant to protect the occupants from fall and the design and materials need to be approved by BCA since submissions are needed. house needs regular cleaning and maintenance so it's either you spend some effort to clean and maintain or take the risk of fall injuries. you could build walls instead of having staricase railings if you don't want the maintenance.

There's plenty of home lifts in the market ranging from cheap chinese brands to high end eurpoean brands. Also there's option of traction lift or platform lift. home lifts are usually customoised for the project to the cabin size will be customised as per requirements as well. get your QP to source for you and then once confirmed, the lift shaft design will be based on the shop drawings the lift contractor provides. make sure you confirm your lift specifications and then have your house designed around it rather than your QP putting in a generic lift shaft size which means you will be stuck with that size and narrow your options of lifts. worse case is you will need to hack your lift shaft if the dimensions are not catered for properly and the internal dimensions cannot fit the lift which was ordered for. another potential issue with no proper specifications is your lift shaft does not have enough overheight for the chosen lift which will also mean more hacking works. When choosing the lift supplier, get all the costing including future maintenance costs. The maintenance costs can vary quite a bit between suppliers even thought the upfront cost is similar. Maintenance is something you need to pay for the entire lifespan of the lift and needs to be done at a minimal quarterly and yearly inspections (for license renewal) with load testing done every few years as well.

[snoozee 98]

13 hours ago, AWS said:

Not sure if it’s true, I have heard from my builder that soil test results are now lodged with BCA/SLA (I am not sure specifically which agency) and if your immediate neighbour has just done rebuild recently, you can use his soil test result on request from that specific agency. Maybe the result can be used as long as it’s not too far away. I may be wrong but there will be cost savings if it’s true. 

nowadays everything seems to need piling. my house was built with huge footings but my neighbouring 2 houses are rebuilt with piling required. so the soil test report sharing thing may or may not be true today. Anyway the cost savings is very marginal so i'd rather pay for that few K for a piece of mind cos one will never know whether there's major differences in soil conditions between the plots even if quite near to each other.

[leechaorui 2]

On 10/25/2024 at 7:58 AM, snoozee said:

nowadays everything seems to need piling. my house was built with huge footings but my neighbouring 2 houses are rebuilt with piling required. so the soil test report sharing thing may or may not be true today. Anyway the cost savings is very marginal so i'd rather pay for that few K for a piece of mind cos one will never know whether there's major differences in soil conditions between the plots even if quite near to each other.

How do you build on footing if there is a sewage line that cut across your house?  Do you know how much does it cost to do a trench and what are the limitations of building above the trench?

[snoozee 98]

On 11/1/2024 at 7:36 PM, leechaorui said:

How do you build on footing if there is a sewage line that cut across your house?  Do you know how much does it cost to do a trench and what are the limitations of building above the trench?

every site is different so it depends on the location of the sewer line. from SIP, there will be a rough location of where the sewer line is so the PE can determine the foundation design. in any case, my PE designed the footings such that the RC trench for the sewer line running across my plot is situated between 2 sets of footings.

cost of trench will depend on length of sewer which needs to be protected and depth of the sewer pipe. for anything that requires more than 1.5m in excavation, ERSS will need to be erected to prevent soil collapse so the ERSS is a big cost. if the sewer is more than 3m deep (up to 5m), the width of the trench will be bigger as well. so instead of a 1m wide trench, a 1.5m wide trench will be needed. this means the ERSS cost will go up as well.

officially, there should not be anything done above the trench as it will need to be accessible for any works required by PUB. but I think most owners will just cover over the trench after inspection is done and approved. of cos, this is done at owner's own risk since the structure/furnishings above the trench will need to be hacked away should PUB request for it,

[leechaorui 2]

For trench, what are the associated cost related to submission, testing/ inspection, besides the actual construction cost?  One contractor quoted me $100,000 for building the trench which is probably about 20m long that cut across the width of my house.  Seems very costly.

What is the difference between steel construction vs traditional construction methods?  Is steel construction more prone to corrosion and rust, less stable and unable to take higher weight loading compared to traditional methods?

Edited November 5 by leechaorui

[snoozee 98]

13 hours ago, leechaorui said:

For trench, what are the associated cost related to submission, testing/ inspection, besides the actual construction cost?  One contractor quoted me $100,000 for building the trench which is probably about 20m long that cut across the width of my house.  Seems very costly.

What is the difference between steel construction vs traditional construction methods?  Is steel construction more prone to corrosion and rust, less stable and unable to take higher weight loading compared to traditional methods?

I don't recall any fees involved. If there were any, the fees would have been parked under my construction cost as there was no additional fees I had to pay for the trench.

100k for a 20m trench doesn't seem high. I had to pay 80k+ for a 8m+ long 3m deep trench which involves ERSS works. you can choose not to build the trench, just design your house smaller and set it away from the sewer line.

steel construction is supposed to cut down the construction period required since bolting/welding on steel beams and columns is faster than setting up the rebars, creating formwork and concrete pour. but I've seen some projects in my estate which used steel construction and the construction time seems to be the same as traditional construction. so i don't get why need to pay more but still end up waiting the same length of time. I don't think steel construction will be more prone to corrosion issues. Else BCA would not have approved this method which is also used in many commercial buildings. weight loading shouldn't be an issue since the steel beam sizing and design will be based on what PE mandates in the structure design.

[leechaorui 2]

You are right that I could design and build away from the sewage line.  It would mean that the house would be much smaller, probably by about more than half its potential is loss.

The other good thing about building a not so big house is to have a bigger backyard garden and a smaller property tax bill.

Do you know how is property tax computed and what is the expected property tax for a built up GFA of about 6,000 sqft in Seletar Estate?

 

[snoozee 98]

11 hours ago, leechaorui said:

You are right that I could design and build away from the sewage line.  It would mean that the house would be much smaller, probably by about more than half its potential is loss.

The other good thing about building a not so big house is to have a bigger backyard garden and a smaller property tax bill.

Do you know how is property tax computed and what is the expected property tax for a built up GFA of about 6,000 sqft in Seletar Estate?

 

property tax is not totally based on the size of your house. it is based on annual value. To quote IRAS,

"The AV of buildings is the estimated gross annual rent of the property if it were to be rented out, excluding furniture, furnishings and maintenance fees. It is determined based on estimated market rentals of similar or comparable properties and not on the actual rental income received."

To put it simply, a 50 years old run down 6000sqf house will have a much lower AV than a brand new 6000sqf house since the brand new house will definitely fetch more rent compared to the old house.