Assumptions of the 3-story apartment
by Hanlin » Mon Aug 07, 2006 11:22 pm
All of the assumptions:
1. 3-floors apartment
28 units studio: wide is 14', length is 23'
Parking spot: wide is 10', length is 16'
Stair’s structure: wide is 11.5', length is 18'
one Laundry room & Warehouse: wide is 14', length is 23'
Wall－wood word is 2×6 for each, total is
Concrete topping is 1.5×1.5 for each
Anti-Fire Requirement: R2 or R3 (the cheapest one)
One window for each unit: wide is 6’, length is 2.4’
No balcony
No handicap allow
2. Fundamental Structure:
Soil-sandy base, using spread footing system
3. Construction:
Time schedule-6 months
4. Structure Material: Wood Frame, wood floor and wall, with 1 1/2 inches
concrete topping.
5. Out wall decorate: stucco
Comments to Project Design Assumptions
by ken » Tue Aug 08, 2006 10:28 am
**8/8/06
Comments to Org. Assumptions:
All of the assumptions:
1. 3-floors apartment (ok)
28 units studio: wide is 14', length is 23' (kind of small, but ok)
Parking spot: wide is 10', length is 16' (ok, can be smaller - no handicapped space)
Stair’s structure: wide is 11.5', length is 18' (ok)
one Laundry room & Warehouse: wide is 14', length is 23' (ok)
Wall-wood word is 2×6 for each, total is (ok)
Concrete topping is 1.5×1.5 for each (see notes below)
Anti-Fire Requirement: R2 or R3 (the cheapest one) (choose R-2)
One window for each unit: wide is 6’, length is 2.4’ (need more windows, revise)
No balcony (ok)
No handicap allow (ok)
2. Fundamental Structure:
Soil-sandy base, using spread footing system (see notes below)
3. Construction:
Time schedule-6 months (6-9 months average including site work)
4. Structure Material: Wood Frame, wood floor and wall, with 1 1/2 inches (see notes below)
concrete topping.
5. Out wall decorate: stucco (ok)
================================================
**8/8/06
New Functional Assumptions:
A. Building Code Requirements & Design Parameters
-Building Code: IRC 2003
-Use and Occupancy Classification: R-2
-Type of Construction V-A (Combustible 1-hour fire rating)
Sprinkle system or 2-hour fire seperation at common corridor and stair (steel-pan system)
-Wind: 105 mph (3-second gust) Exposure C
-Seimic Design Category: B
-Overall Building Height: 30 ft. max. height
-Parking space: 8'-6" min. x 17'-0" min.
-Stair Exits (2 min.) 8'-0" min. wide x 12'-0 long with landings
(Steel stringers and 2" concrete topping over steel corrugated deck pan)
B. Sitework Design Criteria:
-Civil work: Land survey, site plan, etc.
-Utility Line Hookup: etc.
-Site preparation: etc.
-Excavation: (per soil condition)
-Soil report: Soil boring drilling (use this to determine the foundation system)
-Drainage: (per design)
-Shoring: (assumed no shoring is required at the existing building or soil condtion)
-Misc.
C. Architectural Design Criteria:
-Roof: Composite Shinge Roofing Systems
-Exterior Siding: Stucco (or equivalent)
-Window: Galzing window (opening area should meet building code requirements)
-Automatic Sprinke System: At corridor only (2-hour fire rated wall is optional)
-Mechanical room, storage room, etc. (per design)
-Stari Exits: Steel-pan pre-engineered stari system
-Lighting: Fixtures, etc. (per design)
-Story Height: 10'-0 max. total height
-Wall systems: 2x6 at 16" o.c. exterior and at cooridor walls; 2x4 at 16" interior wall
(2) 2x4 at 16" 0.c. at demised common seperation walls between units
Common wall is about 10" thick - used as bearing wall
Lower story wall: all stud spacing is at 12" o.c., upper 2-story is at 16" o.c.
-Floor framing: 1-1/2" gypcrete topping or light-weight concrete topping over wood floor framing
-Fire Rated Wall: 1-hour (two layers of 5/8" Gypsum-X Sheetrock walls and 2x studs)
-Insulation: R-12 to R-20 (per design)
-Mechanical: Duct work, AC units, etc. (per design)
-ELectrical: (per design)
-Plumbing: (per design)
-Misc. (per design)
D. Structural Design Criteria:
-Design loads: Roof Snow load: 30 psf (ground snow load: 30 psf)
Roof Dead Load: 25 psf
Floor live load: 40 psf Floor dead load: 10 psf
Public area live load: 100 psf
-Foundation: Spread footing (36" wide by 12" deep with 3-#5 rebar bot. continuous)
Stem wall (10" wide x 2'-0" min. stem height over footing) at front/back/corridor walls
Interior column footing 6'-0 sq. x 12" deep (7-#5 bot. each way)
-Roof framing: Pre-engineered trusses @ 24" oc. spanning between front/back wall to corridor walls)
-Floor framing: 11 7/8" TJI-pro 210 floor joist at 16" o.c. spanning side-to-side to common walls between units
3/4: T&G subfloor above floor joists
-Wall framing: 3rd/2nd floor framing: 2x6 at 16" o.c. exterior; 2x4 at 16" interior; (2)2x4 at 16" common walls
1st floor framing: 2x6 at 12" o.c. exterior; 2x4 at 16" interior; (2)2x4 at 12" common walls
-Columns: (6) 2x4 at common walls at 14'-0" o.c.
-Headers: (2) 9-1/2" TJ Microm Lam at each door and window openings (Span= 6'-0" max. add one for greater span)
-Connectors: at the roof or other framing (add 5% of structural framing system cost)
E: Facility Management:
-Architectural interior, laundry room, garage collection, etc. (per design)
F: Maintenance:
- AC units, light, etc. (per design)
G: Misc. (per design)
Avg. Cost Data Per Your Info.
by ken » Sun Aug 13, 2006 9:56 am
Using you data, you will have an average construction cost:
Avg. Cost= $768089 / 14655 sf = $52.4/sf (using living area will give you a conservative cost indicator)
This falls in my average cost summary table:
Type 2B (based on NBC90 old building code) the fourth one in series
Avg. Cost Range: $52.4 to $72.2/sf
So, you are in the right direction.
Use RS Means to compute each "component" price per squre footage,
then you can get an average "component" price according to Means book
and refine your total construction cost. (Should be a little more than $52.4/sf).
You may want to validate and include some of the fire-seperation and exit/stair construction cost. (ex. sprinkling system in the walkway or fire-rated wall requirements-1 hour min., steel-pan stairs, etc.)
It is difficult to estimate the minmum total cost because you have to imagine and consider all the construction processes.
If you have any question regarding a particular component, please let me know. Thanks for the updated info.
