MA General Contractor cheat sheet

780 CMR is the Massachusetts State Building Code; it adopts the International Building Code with Massachusetts amendments and applies statewide.

The Board of Building Regulations and Standards (BBRS) adopts and amends 780 CMR; local building inspectors enforce it day to day.

One- and two-family dwellings are designed under the code's residential provisions, which include prescriptive tables for spans, egress, and energy.

Decisions of a local building official may be appealed to the state Building Code Appeals Board, generally within 30 days of the decision.

521 CMR, the Architectural Access Board regulations, governs accessibility in public and commercial buildings and is enforced in addition to the building code.

Work on existing buildings is classified as repair, renovation, alteration, addition, or change of use; a change of use or substantial alteration can trigger upgrade requirements.

Occupancy group (A, B, E, R, M, S, F, U) and construction type set allowable height and area from the code tables.

Where the code and a manufacturer's listed instructions differ, the more restrictive requirement governs, and listed assemblies must be installed per their listing.

Energy requirements sit in 225 CMR 22 for residential and 225 CMR 23 for commercial work, with a stricter Stretch Code for Green Communities.

The building official must grant or deny a permit application within 30 days for one- and two-family dwellings and within 45 days for all other buildings.

Building permits lapse when work has not commenced within six months or has been suspended for a continuous six months; local ordinances set the exact period.

Standard inspection points: excavation and footing before concrete, foundation and waterproofing before backfill, framing and rough-in before insulation, final at completion.

Separate permits and separate inspectors apply to electrical, plumbing, gas fitting, and sheet metal work.

A certificate of occupancy is required before a new building is occupied or an existing building changes use; a conditional temporary certificate may be issued.

Zoning relief runs through the local board of appeals: appeals within 20 days, and variances or special permits require a public hearing and a filed written decision.

Work in or near wetlands or floodplains requires a Notice of Intent to the Conservation Commission and an Order of Conditions before soil is disturbed.

Septic systems and wells require local Board of Health approval under Title 5 (310 CMR 15.000) before or together with the building permit.

The permit and approved plans must remain on site; a stop-work order halts all work until the cited condition is corrected and released.

A valid contract requires offer, acceptance, consideration, capacity, and a lawful purpose.

Contracts that cannot be performed within one year must be in writing under the statute of frauds; change orders should be written and signed before work proceeds.

M.G.L. c. 93A prohibits unfair or deceptive acts in trade or commerce; a written demand letter must be sent at least 30 days before filing suit.

Home improvement contracts must be written, show the contractor's HIC registration number, and give the homeowner a three-business-day cancellation right when signed at the home.

Massachusetts recognizes an implied warranty of good and workmanlike construction, independent of any express written warranty.

Contract documents should define scope, price, payment schedule, retainage, schedule, change-order procedure, warranty, insurance, indemnity, and termination.

Progress payments should be tied to executed conditional lien waivers so releases match money actually received.

Time-is-of-the-essence clauses, liquidated damages, and no-damages-for-delay clauses are enforceable but strictly construed against the drafter.

Dispute resolution clauses set the forum (mediation, arbitration, court venue); arbitration is not required unless the parties agreed to it.

M.G.L. c. 254 governs mechanic's liens; the lien is generally recorded in the registry of deeds within 90 days after the last day labor or materials were furnished.

A subcontractor perfects a lien by recording a Notice of Contract and later a Statement of Account; the general contractor's contract with the owner is the lien basis.

A civil action to enforce the lien must be commenced within 90 days after recording the statement of account, or the lien dissolves.

On owner-occupied one- to four-family homes, subcontractors and suppliers have limited lien rights unless the owner authorized or consented to the work in writing.

Massachusetts applies a strict three-part (ABC) test for independent contractor status: freedom from control, work outside the usual course of business, and an independently established trade.

Workers' compensation insurance is mandatory for any employer with at least one employee; collect certificates of insurance from every subcontractor before mobilization.

Home Improvement Contractor (HIC) registration is required for residential remodeling; an unregistered contractor cannot enforce the contract and faces fines.

The Home Improvement Guaranty Fund can reimburse homeowners for losses caused by registered contractors, subject to statutory claim limits.

Retain contracts, change orders, permits, payroll records, and insurance certificates for at least six years, matching the contract statute of limitations.

Sheet order commonly runs general (G), civil (C), architectural (A), structural (S), mechanical (M), electrical (E), plumbing (P).

At 1/4 in = 1 ft, one quarter inch on paper equals twelve inches in reality; confirm with the graphic scale whenever a sheet has been reduced or enlarged.

Plans give width and length, sections give height and assembly, elevations give exterior appearance; cross-check all three before layout.

Grid and column lines anchor dimensions and details; dimension strings are read to the nearest structural or finish face they reference.

Door and window schedules key by mark (D-3, W-5) and list size, type, glazing, fire rating, and hardware.

Detail callouts show detail number over sheet number (5/A-501); section marks show the cut location and direction of view.

Revision clouds and deltas flag changes; the latest revision date and the issued-for-construction stamp govern the work.

Elevation datum is often set at the first floor; confirm whether dimensions run to structural or finish surfaces.

Site plans show property lines, setbacks, benchmark, utilities, flood zone, north arrow, and erosion and sedimentation controls.

Board feet = thickness in inches times width in inches times length in feet, divided by 12.

Concrete cubic yards = length times width times depth, all in feet, divided by 27; add 5 to 10 percent for waste and over-excavation.

Gross margin = markup divided by (1 + markup); a 20 percent markup on cost produces only a 16.7 percent margin on price.

Takeoff follows construction sequence: excavation, concrete, masonry, framing and lumber, envelope, MEP rough-in, insulation, finishes.

Typical waste factors: framing lumber 5 to 10 percent, roofing shingles 10 percent plus starter and ridge, drywall and tile 10 to 15 percent.

Square a layout with the 3-4-5 triangle or by comparing diagonals; equal diagonals confirm a true rectangle.

Set batter boards and string lines outside the excavation limits so stakes survive digging, and transfer the benchmark to a protected point.

A story pole marked with floor-to-floor heights, plate heights, and window head heights keeps elevations consistent across the crew.

Percent slope equals rise divided by run times 100; a 4:12 roof pitch is a 33 percent slope.

Massachusetts law requires notifying Dig Safe (811) at least 72 hours before excavation and waiting for utility marks before digging.

OSHA 1926 Subpart P requires a protective system at 5 ft depth in trenches; excavations 20 ft or deeper need a registered professional engineer's design.

Provide a ladder, stair, or ramp within 25 ft of lateral travel in any trench 4 ft or deeper.

Spoil and equipment stay at least 2 ft back from the excavation edge, and a competent person inspects daily and after rain.

Footings bear on undisturbed soil below the frost line, roughly 42 to 48 in in Massachusetts, and at least 12 in below finished grade.

Erosion control before grading: silt fence on the downslope perimeter, stabilized construction entrance, and inlet protection.

Backfill in lifts of about 8 to 12 in, compact to the specified density (commonly 95 percent standard Proctor), and protect foundation drains.

Confirm bearing capacity and footing size from the soils report or code tables; a proof roll reveals unsuitable subgrade.

Work in wetlands requires a Notice of Intent to the Conservation Commission and an Order of Conditions before any soil disturbance.

Specified strength f'c is verified on 28-day cylinder breaks; the mix water-cement ratio controls both strength and durability.

Slump per ASTM C143 measures workability; adding water on site raises the water-cement ratio and lowers strength.

Vibration consolidates concrete; over-vibration causes segregation. Screed, float, and cure to limit plastic shrinkage cracks.

Cure concrete moist for at least 7 days; vertical forms may come off after 24 to 48 hours, structural forms only after strength is verified.

Reinforcement cover is about 3 in where cast against earth and 1.5 to 2 in on exposed formed surfaces.

Standard concrete masonry units are 8 by 8 by 16 in nominal; mortar joints are typically 3/8 in and are tooled when thumbprint hard.

Masonry veneer requires a drainage plane, base flashing, and weep holes spaced not more than 24 in on center above the flashing.

Grout lifts are limited in height and must be puddled to fill cells completely; reinforcement is positioned and inspected before grouting.

Control and expansion joints accommodate movement; place brick expansion joints at corners, offsets, and intervals set by code to prevent random cracking.

Notches at joist ends may not exceed one quarter of the depth; notches elsewhere may not exceed one sixth of the depth.

Holes may not exceed one third of the joist depth, must be at least 2 in from the top and bottom edges, and belong in the outer thirds of the span.

Bearing is at least 1-1/2 in on wood or metal and at least 3 in on masonry, with mechanical connection to prevent rotation.

Match span tables to species, grade, size, spacing, and live load; verify the grade stamp or use an engineered design.

Studs run 16 or 24 in on center; openings need a table-sized header plus king and jack studs, with a sill at windows.

Lay out from one reference line, crown joists upward, and install solid blocking at bearings and over supports.

Subfloor panels run long dimension across joists with 1/8 in edge gaps, glued and nailed per schedule, and staggered end joints.

Trusses may not be cut, notched, or field-modified without a registered engineer's approval; install temporary and permanent bracing per the truss design.

Fire blocking is required in concealed spaces between floors, at soffits and dropped ceilings, and around penetrations through top plates.

Asphalt shingles need a 4:12 minimum for standard application; 2:12 to 4:12 requires double underlayment, and below 2:12 a membrane roof is required.

Ice barrier membrane runs along the eaves from the roof edge to at least 24 in inside the interior wall line, and through valleys in cold climates.

Drip edge goes under the underlayment at eaves and over it at rakes; underlayment laps shingle-style with upper sheets over lower.

Flashings: step flashing at sidewalls, kick-out flashing where a roof meets a wall, pan flashing at decks and chimneys.

Fasten shingles with 6 nails in high-wind zones, driven above the exposure line through the nailing strip; 4 nails is the minimum elsewhere.

Weather-resistive barrier is installed shingle-lap over the framing with sealed penetrations, and siding is held at least 6 to 8 in above grade.

Window flashing sequence: sill pan first, then jambs, then head; back-dam the sill and integrate the assembly with the water-resistive barrier.

Attic ventilation: about 1 sq ft of net free vent area per 150 sq ft of ceiling, or 1/300 when vents are balanced and a vapor retarder is present.

Decks and porches need a flashed ledger, corrosion-resistant fasteners, and positive slope of walking surfaces away from the house.

225 CMR 22 covers residential and 225 CMR 23 covers commercial energy performance; both adopt the IECC with Massachusetts amendments.

Climate zone 5 prescriptive values commonly used: ceiling R-49, wood-frame wall R-20 or R-13 plus 5 continuous, basement wall R-15/19, slab R-10, windows U-0.30.

Air leakage is verified by a blower-door test measured in air changes per hour at 50 pascals; the Stretch Code threshold is stricter than the base code.

Insulation must stay in continuous contact with the air barrier without gaps or compression, and eave baffles must preserve attic vent space.

Ducts and air handlers located in unconditioned space must be sealed and insulated, and duct leakage testing may be required.

Recessed luminaires penetrating the envelope must be insulation-contact rated and air-sealed to keep the barrier continuous.

Windows and doors must carry NFRC labels showing U-factor and solar heat gain coefficient that meet or beat the scheduled values.

Tight envelopes require whole-house mechanical ventilation, typically an exhaust or balanced HRV/ERV system meeting ASHRAE 62.2.

A compliance report or HERS certificate must be posted at the job and given to the owner at completion.

OSHA 29 CFR 1926 governs construction; fall protection is required at 6 ft, with top rails at 42 in plus or minus 3 in and midrails at 21 in.

Extension ladders are set at a 4:1 slope, extend 3 ft above the landing, and are secured at the top.

Scaffolds must be fully planked with guardrails on all open sides and tied to the structure when height exceeds four times the base width.

Trenches need a protective system at 5 ft, access within 25 ft of travel, spoil 2 ft back, and daily competent-person inspection.

All 120-volt, 15- and 20-ampere receptacles on site require GFCI protection or an assured equipment grounding conductor program.

Silica exposure from cutting masonry or concrete is controlled with water or vacuum dust collection and Table 1 respiratory protection.

Massachusetts requires workers' compensation insurance for any employer with one or more employees, with proof posted on site.

Housekeeping and access: keep walkways clear, cover or guard floor openings, and keep material stacked back from edges.

Hazard communication requires safety data sheets on site, labeled containers, and PPE selected from the hazard assessment.

Sequence plumbing, electrical, and HVAC rough-in before the framing inspection and insulation; each trade pulls its own permit and gets its own inspection.

GFCI protection is required in kitchens, bathrooms, garages, outdoors, and within 6 ft of sinks; AFCI protection covers most dwelling branch circuits.

Electrical panel working clearance is 30 in wide, 36 in deep, and 6 ft 6 in high, kept free of storage.

Box fill is limited by conductor count and device size under NEC 314.16; overfilled boxes are a common inspection failure.

Smoke alarms are interconnected in each bedroom, outside sleeping areas, and on every level; CO alarms go near sleeping areas where fuel-fired appliances exist.

Drain waste and vent pipe 3 in and smaller slopes 1/4 in per ft, and vents must terminate the code-required distance above and from roof openings.

Water heater temperature and pressure relief discharge must run full size by gravity to a safe location with no trap, valve, or reduction.

HVAC sizing uses Manual J and duct design uses Manual D; seal ducts and provide combustion air plus condensate drainage.

Firestopping is required where pipes, ducts, and cables penetrate rated assemblies, so sleeves and blocking must be coordinated with the framing layout.