Lancaster

First confirm that the parcel is in a district where single-family dwellings are permitted or allowed; § 220-9.1 treats that as a Residential Zoning District for ADU purposes. Also check the official zoning and overlay maps.

For a Protected Use ADU, Lancaster states that dimensional standards may be no more restrictive than those applied to a residential dwelling or accessory structure in the same district. For a Local ADU, both the structure and lot must comply with Article IV and § 220-11. Existing nonconforming structures do not automatically disqualify a Protected Use ADU, but the work must still comply with the building code, 760 CMR 71.00, and state law.

Do not use a single townwide setback number. The applicable front, side, and rear yards depend on the zoning district, the proposed ADU form, the status of existing structures, and overlays. Section 220-11 generally addresses yard dimensions and states that a rear-yard accessory structure may not be closer than 15 feet to a lot line; confirm whether that accessory-structure standard or the principal-dwelling standard governs the proposed ADU.

A certified plot plan may be required to show lot lines, existing and proposed structures, required setbacks, easements, septic systems, wells, and driveways. Wetland buffers or other site controls may further limit placement.

Lancaster requires ADU construction to comply with Title 5. On a septic-served property, bedroom count, existing design capacity, reserve area, system condition, soils, and the proposed configuration may affect feasibility and may require an upgrade. The Lancaster Board of Health enforces Title 5 and oversees septic installation and maintenance.

Massachusetts guidance says a Protected Use ADU must comply with applicable Title 5 requirements. A local requirement beyond Title 5 must still satisfy the state's reasonableness test. On a sewer-served property, confirm available capacity and any connection or upgrade requirements with the applicable local authority. Do not assume service from an address alone.

Confirm whether the property uses a private well or public water. For a private well, verify water quantity, water quality, and required separations from septic components and proposed construction with the Board of Health and qualified professionals. For public water, confirm service and capacity with the applicable provider. Lancaster's certified plot-plan guidance notes that wells and septic systems are commonly shown because they can affect a proposed building location.

The Lancaster Conservation Commission administers the Massachusetts Wetlands Protection Act and the Lancaster Wetlands Protection Bylaw. Work near wetlands, streams, riverfront area, vernal pools, or other resource areas may require a Request for Determination of Applicability, Notice of Intent, or other Conservation Commission review.

Town materials identify a local 25-foot no-build or no-alteration area around wetlands and vernal pools. Confirm current boundaries and requirements with the Conservation Commission; do not rely solely on online mapping for design or permitting.

Lancaster has significant historic and archaeological resources and an active Historical Commission. This review did not verify that every historic or National Register property is subject to a separate local design approval. If the parcel is within a historic area, contains a listed resource, or involves an older building, ask Inspectional Services and the Historical Commission whether any demolition, exterior-design, or archaeological review applies before finalizing the ADU design.

Utility feasibility is property-specific. Confirm whether the parcel has public sewer and water or relies on septic and a private well. Review service capacity, connection or upgrade needs, electrical service, trenching, grading, drainage, and emergency access early. A municipality may not impose an unreasonable separate-connection requirement on a Protected Use ADU, but a utility, board, commission, or applicable state law may require work where capacity or health and safety standards justify it.

Property feasibility may also depend on floodplain or other overlay districts, lawful status of existing structures, easements and rights-of-way, driveway and emergency access, grading and drainage, stormwater controls, ledge, retaining walls, tree removal, and space for construction access. Review the official zoning and overlay maps and obtain a survey or certified plot plan when required. A protected-use classification does not waive building, fire, environmental, or sanitary codes.