Sectors Served
The answer changes with the building. This page sets the kinds of property the site's sourced facts reach against the rules that apply to each, and says plainly where the sourced material runs out.
A roof question has a different answer for each building
This page sorts the buildings a Massachusetts reader is likely to own, buy or sell by what the sourced rules say about each one. It covers a single-family house, a two-family house, a three- or four-unit building, a pitched roof over a vented attic, and a commercial or non-owner-occupied flat roof. For each, it says which rule applies and where the sourced facts run out.
Owner occupancy matters more than most readers expect. Several rules this site relies on are written for one- to four-unit homes that a person lives in, and one of them stops at one- and two-family houses. A landlord or a commercial owner may fall outside the owner-occupied rules altogether, so the table does not stretch them to cover a building they do not reach.
We would rather say where a rule stops than guess at the next building along.
Nothing here ranks one kind of building as the better job to re-roof. The page reports what applies and what does not, and leaves the decision with the reader and the people who inspect the house.
Rules by building type, side by side
| Building | Rule that applies | Where the sourced fact stops | Source |
|---|---|---|---|
| Single-family house, owner-occupied | A home improvement contract must be in writing, carry the contractor's registration number and a scheduled completion date, and cap the deposit at one-third of the price, with an exception for certain special-order materials. | The rule does not say which roof, siding or window jobs count as ordinary repairs for a permit. A town building department decides that. | M.G.L. c. 142A, section 2; Town of Dracut permit guidance |
| Two-family house, owner-occupied | The same contract rule applies. The roof-covering supervisor licence class (RF) covers roofing work on one- and two-family dwellings. A homeowner doing permitted work alone is exempt, but becomes the supervisor if they hire people. | The licence class covers roof covering only. Sheathing or framing work raises a separate question. | 780 CMR 110.R5.1, registration and licensing |
| Three- or four-unit building, owner-occupied | The same contract rule applies, because it covers owner-occupied buildings of one to four dwelling units. | The supervisor licence rule stops at one- and two-family dwellings, so this table states no licence rule for a larger building. | M.G.L. c. 142A, section 2 |
| Pitched roof over a vented attic, any building | The model residential code sizes attic ventilation at 1 square foot of net free vent area for every 150 square feet of attic floor, balanced between eave intake and ridge exhaust. UMass recommends at least R-38 ceiling insulation for northern houses. | These are model-code and university figures. This guide has not confirmed a Massachusetts amendment that would change them. R-38 is a floor, not a target. | Journal of Light Construction, calculating attic ventilation; UMass Amherst, preventing ice dams |
| Commercial or non-owner-occupied flat roof | No sourced rule for this building type. | The owner-occupied contract rule does not reach these buildings, and the site has no sourced fact yet on TPO or EPDM roofs. | None |
| These are rules and sourced figures, not prices and not a quote. Where a rule stops at a building type, the third column says so, and that gap is left open on purpose. | |||
The places a reader stops, and why the answer changes
Does a unit someone else lives in change the rules?
It can. Once a building has a unit that someone else lives in, the owner-occupied rules in the table may stop applying. The contract rule is written for owner-occupied buildings, so check which rule the work falls under before you sign anything, and ask the person who will sign the contract which one they think it is.
Is a flat roof covered here?
Not yet. The site has no sourced fact on TPO or EPDM roofs, so the flat-roof row is left empty rather than borrowing a rule from a pitched house. A flat-roof question needs its own source before this page can answer it honestly. Until then, the reader should take it to a licensed person who inspects that kind of roof.
Does a bigger building change the paperwork?
Possibly, and the sourced material does not say how far. The supervisor licence rule covers one- and two-family dwellings and stops there. For a building with more units, ask the building department which rules apply, and ask the contractor to show the registration number and completion date in writing before work begins.
What should an attic over a pitched roof have?
The model residential code sizes attic ventilation at a ratio of 1 to 150, measured as net free vent area against attic floor area, and it wants intake at the eaves to be equal to or greater than exhaust at the ridge. A 1,500 square foot attic floor works out to 10 square feet of net free area, which is 1,440 square inches. UMass Amherst recommends at least R-38 ceiling insulation for northern houses, continuous and evenly deep. Treat that as the floor a house should meet, not the target.
Use the table row by row, then check your own building
Start with the building type that matches yours, not the one you hope it is. Read the rule in the second column, then the note in the third column that says where the rule stops. If a note stops you, the question goes to the building department or to the person who will sign the contract, not to a guess.
Take the row to your first conversation with an inspector or a contractor, and ask them which row describes your house before they quote. Anyone who prices the job without asking what kind of building it is has skipped the question the table starts with, and that is worth knowing before you sign.
If the real question is whether to fix or replace the roof, the decision-helper on the Resources page takes that up. It works on one exterior problem at a time, and it says plainly what it cannot see.
