Manufactured vs. Modular Homes

How Modular Homes and Manufactured Homes Differ

by Janet Wickell

What Are Site Built Homes?

They are constructed entirely at the building site.
They conform to all state, local, or regional codes where the house is located.
Often called "stick-built" houses.
A well-built, cared-for site-built home generally increases in value over time, although its location plays a key role in value.

What Are Modular Homes?

Modular homes are built in sections at a factory.
Modular homes are built to conform to all state, local, or regional building codes at their destinations.
Sections are transported to the building site on truck beds, then joined together by local contractors.
Local building inspectors check to make sure a modular home's structure meets requirements and that all finish work is done properly.
Modular homes are sometimes less expensive per square foot than site built houses.
A well-built modular home should have the same longevity as its site-built counterpart, increasing in value over time.

What Are Manufactured Homes?

Formerly referred to as mobile homes or trailers, but with many more style options than in the past.
Manufactured houses are built in a factory.
They conform to a Federal building code, called the HUD code, rather than to building codes at their destinations.
Manufactured homes are built on a non-removable steel chassis.
Sections are transported to the building site on their own wheels.
Multi-part manufactured units are joined at their destination.
Segments are not always placed on a permanent foundation, making them more difficult to re-finance.
Building inspectors check the work done locally (electric hook up, etc) but are not required to approve the structure.
Manufactured housing is generally less expensive than site-built and modular homes.

HUD vs IRC Comparison Table

HUD	MODULAR
1. Frame remains on home	1. Removeable frame which is returned to plant
2. 2″x6″ or 2″x8″ Floor Joists 16″ OC	2. 2″x10″ Floor Joists 16″ OC
3. Single 2″x6″ (or 2″x8″) Rim Rail Around Floor	3. Double 2″x10″ Rim Rails Around floor
4. Exterior walls have 2″x6″ Top Plates and 1″x6″ Bottom Plates	4. Exterior walls have Double 2″x6″ Top Plate and 2″x6″ Bottom plate
5. Cedar Canyon, Cedar Canyon LS & Pinehurst Interior walls with 2″x4″ studs 24″ OC with 2″x4″ Top Plate and 1″x4″ Bottom Plate	5. Cedar Canyon, Cedar Canyon LS & Pinehurst Interior walls with 2″x4″ studs 24″ OC with 2″x4″ Top & Bottom Plates
6. Grand Manor Interior walls with 2″x4″ studs 16″ OC with 2″x4″ Top Plate and 1″x4″ Bottom Plate	6. Grand Manor Interior walls with 2″x4″ studs 16″ OC with 2″x4″ Top and Bottom Plates
7. 30# Roof Load (HUD Rafter)	7. 30# Roof Load (IRC Modular Rafter)
8. Roof Pitches: 2.66:12 on 40 Wides, 4:12 on 28 Wides with 14″ eaves, 3.31:12 on 30 Wides & 44 Wides with 12″ eaves	8. Roof Pitches on all houses at 3:12 with 12″ eaves
9. Insulation R-40 Roof, R-21 Wall, R-33 Floor	9. Insulation R-50 Roof, R-21 Wall and R-30 Floor (some jurisdictions require R-5 Foam insulation on exterior walls
10. 5/8″ Tongue & Groove OSB Floor Decking	10. 3/4″ Tongue & Groove OSB Floor Decking
11. Typical Window & Door Headers are single 2″x6″ Lay Flat Headers (depend on size of window and roof load)	11. Double Vertical 2″x4″ Window & Door Headers (depend on size of window opening and roof load)
12. 7/16″ OSB Underlayment w/House Wrap installed under Lap and vinyl siding only–Not installed under Smart Panel	12. 7/16″ OSB Underlayment w/House Wrap installed under all exterior sidings
13. 3/8″ Facia Board	13. 5/4 Facia Board
14. 40 Gallon Electric Water Heater (50 gallon in Grand Manor)	14. 50 Gallon Electric Water Heater
15. Plumbing with auto vents and some vents through roof	15. All plumbing vents through roof
16. No Water Softener Plumbing Loop required	16. Water Softener plumbing loop (only required in certain jurisdictions)
17. Drain water system complete	17. Drain system plumbed through floor with on site work required
18. 1-1/2″ Drain and P-traps	18. 2″ Drain and P-traps on tubs & showers
19. 1″x6″ Sub Facia	19. 2″x4″ Sub Facia
20. Whole House Water Shutoff Valve included in laundry plumbing hook up box	20. Separate Whole House Water Shutoff valve box
21. Cedar Canyon, Cedar Canyon LS and Pinehurst with non-FHA grade carpet, Grand Manor with FHA grade carpet	21. FHA Grade Carpet
22. Smoke detectors in all bedrooms and in living areas	22. Smoke detectors inside each bedroom and outside each bedroom area and in living areas
23. High Efficacy Lighting Not Required	23. 75% High Efficacy Lighting