Trade Topics
September 2005
Selective Demolition Costs
The figure of $1.00 - $2.00 per square foot of building area, for comprehensive demolition (the entire building interior), should not be applied in scenarios where only a portion of the walls and other finishes are to be removed to make way for a new tenant. The following is a guide to estimating selective demolition.
The tables below are set up so that one can estimate the approximate cost of office demolition by inserting quantities in the quantity columns and totaling the extended amounts. Keep in mind that these costs are what the general contractor expects to pay to have the work done, the cost to the client will be higher based on: a) the scope of the entire work, b) the portion of the contractor's general conditions attributable to the demolition and c) the contractor's markup.
The most conspicuous feature in a building interior demolition project is the existing office 'hard wall' partitions. For the purpose of estimating partition demolition one distinguishes two types of partition wall: Type (1): Partitions that end at the acoustic ceiling (under grid ), Type (2) Partitions that extend through the acoustic ceiling (through grid).
The difference between the two types is apparent at the intersection of the wall and the acoustic ceiling.
- In the case of Type 1 walls, (under grid) there will not be any horizontal metal trim visible on the wall where the ceiling meets it because the ceiling is continuous and the partition has been installed 'under' the ceiling.
- In the case of Type 2 walls, (through grid) there will be a horizontal metal (usually white) trim visible on the wall where the ceiling meets it because the wall extends through the ceiling and the installation requires metal trim to act as a shelf upon which the abutting edge of the ceiling tile can rest.
Frequently both types of walls occur in a typical office area. Most interior walls in modern buildings are non- bearing and can be removed. Minimum charge for any trade work will be $450.00.
No. |
Item |
Notes |
Unit |
Unit cost |
1 |
Under grid walls (Type 1) |
No patching of grid required in most cases |
L.F. |
$14.00 |
2 |
Through grid walls (Type 2) |
Acoustic ceiling must be patched |
L.F. |
$18.00 |
3 |
Electrical demolition at walls |
Take total l.f. of both types of walls being removed and divide by 20, round number up |
Units |
$95.00 |
4 |
Patch remaining walls (scars) |
Count intersections where demolished walls abut remaining walls |
Each |
$170.00 |
|
Often, when an area is densely built out with small offices whose walls penetrate the grid, it makes sense to take out the grid as well and replace it with new grid and tile. In this case one would classify all the walls as 'under grid' and add the cost of ceiling demolition and replacement. Depending on the age of the electrical fixtures it may make economic sense to replace them as well.
No. |
Item |
Notes |
Unit |
Unit cost |
5 |
New Ceiling |
Remove and replace ceiling with new ceiling: 2' x4' grid, flush tiles |
S.F. |
$1.90 |
6 |
New light fixtures |
Number of fixtures is determined by multiplying area by 1.3 and dividing product by 107 |
Each |
$195.00 |
7 |
New light switches |
If needed - install new switches |
Each |
$175.00 |
|
Additional common items of selective demolition are:
No. |
Item |
Notes |
Unit |
Unit cost |
8 |
Demising wall -18' |
To a height of 18 feet |
L.F. |
$20.00 |
9 |
Demising wall - 26' |
To a height of 26 feet |
L.F. |
$25.00 |
10 |
Carpet |
Glue down or padded |
S.F. |
$0.28 |
11 |
Vinyl tile |
Remove and scrape mastic |
S.F. |
$1.10 |
12 |
"Hard" ceiling |
Remove drywall ceiling and framing |
S.F. |
$1.25 |
13 |
Ceramic floor tile |
Remove tile and mortar |
S.F. |
$2.50 |
14 |
Acoustic ceiling and lights |
Demo ceiling and light fixtures |
S.F. |
$0.85 |
|
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