Massachusetts Condo Quorum & Supermajority Calculator (M.G.L. c.183A §§ 10, 11, 19)

How this calculator works

This is a quorum-and-threshold validator for Massachusetts condominium meetings. Given the total units, the beneficial-interest percentages present in person and by proxy, the vote type, and any master-deed-specified overrides, it returns:

1. Whether quorum has been met (beneficial interest counted toward quorum compared against the master-deed-specified threshold or the simple-majority default under c.183A § 10(c)).
2. The yes-vote beneficial interest required to pass for the vote type (75% of beneficial interest for master-deed amendments under § 11; near-unanimous for condominium termination under § 19; majority of quorum for regular votes and most special assessments under § 17).
3. The current ballot status (PASSED, FAILED, PENDING, or NO-QUORUM) based on the supplied vote tally.

Use the calculator before convening a meeting to confirm the procedural framework; use it during ballot counting to validate the threshold; use it after the meeting to memorialize the outcome in the trustees' minutes.

The relevant M.G.L. c.183A statute

Massachusetts condominium voting is governed by M.G.L. c.183A — the Massachusetts Condominium Act. The key voting provisions:

§ 10 — Organization of unit owners. Establishes that the unit owners form a trust, corporation, or unincorporated association (the "organization") and elect trustees or directors. The trustees adopt the annual budget, manage the common areas, levy regular and special assessments, and enforce the master deed and bylaws. Most operational decisions are within trustee authority under § 10(b); voting on master-deed amendments, termination, and certain special assessments is reserved to the unit owners.

§ 11 — Master-deed amendment. The master deed may be amended only with the consent of at least 75% of beneficial interest, subject to additional consents required by the master deed itself (which may specify higher thresholds or require the consent of affected unit owners for certain categories of amendment). Some amendments — those affecting a unit's boundaries, beneficial-interest percentage, or use restrictions — typically require the consent of the affected unit owner regardless of the percentage vote.

§ 17 — Special assessments. The trustees may levy special assessments for capital repairs, emergency expenses, or other approved purposes; the assessment is allocated by beneficial interest. The master deed may specify thresholds above which unit-owner approval is required (commonly 10-25% of the annual budget); below the threshold, the trustees may act without member vote.

§ 19 — Termination. The condominium regime may be terminated only with the near-unanimous consent of unit owners — the practical default in most Massachusetts condominium documents is 100% of beneficial interest plus first-mortgagee consent for each unit. The statutory minimum is high because termination eliminates each unit owner's separate property interest.

Voting under c.183A is allocated by BENEFICIAL INTEREST in the common areas — not by unit count. Each unit's beneficial-interest percentage is fixed in the master deed at the time the condominium is created. The unit's beneficial-interest percentage determines its share of common expenses, its share of any special assessment, and its voting power on any matter requiring unit-owner approval.

Key thresholds and Massachusetts-specific gotchas

MAJORITY OF TOTAL vs MAJORITY OF QUORUM. The two thresholds produce different outcomes when turnout is low. C.183A uses MAJORITY OF TOTAL beneficial interest for master-deed amendments (§ 11) and termination (§ 19) — the property-rights actions. C.183A uses MAJORITY OF QUORUM (or master-deed-specified threshold) for regular votes and most special assessments — the governance actions. Confusing the two is the single most common voting-error in Massachusetts condominium practice.

A master-deed amendment can fail even with 60% beneficial interest voting yes. The § 11 threshold is 75% of TOTAL beneficial interest. In a condominium where 80% beneficial interest attends and 60% votes yes (75% of voters), the amendment FAILS because 60% beneficial interest is below the 75% total threshold. Boards routinely announce amendments as passed based on majority-of-voters math; this is wrong under c.183A.

The master deed may RAISE but not LOWER the § 11 floor. A master deed specifying 67% for amendments is unenforceable to the extent it falls below the § 11 75% floor for material amendments. A master deed specifying 90% is enforceable as a higher-than-statutory threshold. Counsel should review the master-deed amendment provisions for floor-compliance before any contemplated amendment.

Beneficial interest is the unit of measurement. All c.183A voting math is in percentages of beneficial interest, not in unit counts. A condominium with 100 units does not necessarily have 1% per unit — the master deed allocates beneficial interest by square footage, by appraised value, or by another formula stated in the master deed. Pull the exact beneficial-interest percentages from the master deed when computing voting power.

Massachusetts does NOT formally license community-association managers. The lack of manager licensing does not affect c.183A voting procedures (which depend on the master deed, bylaws, and statute, not on manager credentials). Many Massachusetts condo managers hold the voluntary CMCA, AMS, or PCAM credentials from CAI's Community Association Managers International Certification Board.

Proxies count once for quorum, once for the vote tally. A valid proxy must be in writing, signed by the unit owner, and delivered to the trustees or meeting secretary before the meeting starts. Many master deeds specify a maximum proxy validity period (commonly 90 days). Proxies marked for a specific issue vote only on that issue; general proxies vote at the proxy holder's discretion.

Termination requires near-unanimous consent. Section 19 is the highest threshold in c.183A. Most Massachusetts condominium documents specify 100% of beneficial interest plus first-mortgagee consent for each unit. Lower thresholds in some documents (75% or 90%) are enforceable to the extent consistent with the unit owners' constitutional property rights, but courts review termination provisions carefully for fundamental fairness.

Worked example: regular member vote

Total units 100. Master-deed quorum 50%. Beneficial interest present 30%, by proxy 25%. Vote: regular. Yes 35% beneficial interest, no 20%.

• Total beneficial interest for quorum: 55%. Quorum requirement: 50%. QUORUM MET.
• Vote type: regular. Threshold: majority of quorum. Required: 51% of 55% = 28.05% beneficial interest.
• Yes 35% meets the 28.05% threshold. PASSED.

Worked example: master-deed amendment — the total-beneficial-interest trap

Total units 100. Beneficial interest present 60%, by proxy 20%. Vote: master-deed amendment. Yes 60% beneficial interest, no 20%.

• Total beneficial interest for quorum: 80%. Quorum: 51% (default). QUORUM MET.
• Vote type: master-deed amendment. Threshold: 75% of TOTAL beneficial interest.
• Required: 75% beneficial interest. Yes 60% falls short by 15%. FAILED — even though 75% of voters approved.

This is the trap. The same ballot tally that passes a regular vote (60% beneficial interest is 75% of voters) FAILS a master-deed amendment (60% is only 60% of total). Boards must structure master-deed amendment campaigns to target the total-beneficial-interest denominator — meaning outreach to non-voting unit owners is critical.

Worked example: condominium termination — § 19 near-unanimous

Total units 50. Beneficial interest present 80%, by proxy 15%. Vote: condominium termination. Yes 85% beneficial interest, no 10%.

• Total beneficial interest for quorum: 95%. Quorum: 51%. QUORUM MET.
• Vote type: termination. Threshold: 100% of TOTAL beneficial interest (default).
• Required: 100%. Yes 85% falls short by 15%. FAILED.

Even a strong supermajority is typically insufficient for termination. Most Massachusetts condominium documents specify 100% unit-owner consent plus first-mortgagee consent for each unit. Termination matters require near-unanimous support and active first-mortgagee coordination.

Worked example: special assessment

Total units 200. Annual budget $500,000. Special assessment of $80,000 (16% of budget) — above the 10% threshold specified in the master deed requiring unit-owner approval. Beneficial interest present 40%, by proxy 30%. Vote: special assessment. Yes 50% beneficial interest, no 18%.

• Total beneficial interest for quorum: 70%. Quorum: 51%. QUORUM MET.
• Vote type: special assessment. Threshold: majority of quorum (default; master deed does not specify higher).
• Required: 51% of 70% = 35.7%. Yes 50% meets the threshold. PASSED.

The majority-of-quorum threshold is materially easier to meet than the master-deed-amendment threshold; this is why special assessments typically pass when properly noticed and supported by trustee communication, while master-deed amendments routinely fail.

What this calculator does NOT model

The calculator implements the QUORUM-AND-SUPERMAJORITY math for Massachusetts condominium meetings. It does NOT:

• Validate the substantive form of proxies (signature, witness, delegation chain, validity period).
• Model the specific master-deed amendment provisions that may impose category-by-category thresholds (boundary changes, beneficial-interest reallocation, use restrictions).
• Model the first-mortgagee consent requirement for termination under § 19 or for certain master-deed amendments.
• Validate compliance with the notice requirements that gate the meeting (specified in the master deed and bylaws, not in c.183A directly).
• Model the trustees' authority to adopt rules under § 10(b) without unit-owner approval.
• Compute the dollar amount of a special assessment per unit (use the companion special-assessment calculator for the allocation math).
• Model the c.183A § 17 distinction between regular and emergency special assessments where the master deed specifies different procedures.

For any consequential vote (master-deed amendment, termination, large special assessment), retain Massachusetts counsel with c.183A experience to oversee the meeting procedure, ballot drafting, and post-meeting documentation.

Counting conventions

The calculator measures voting in percentages of beneficial interest. A unit's beneficial-interest percentage is the unit's share of the common areas as stated in the master deed; pull the exact figures from the master deed when computing voting power.

The calculator caps total beneficial interest at 100% — a meeting cannot have more than 100% beneficial interest in attendance even if both present and proxy counts are reported independently. Avoid double-counting: a unit owner attending in person and also represented by a proxy should be counted only once.

For supermajority calculations on TOTAL beneficial interest (master-deed amendment, termination), the threshold is the percentage of total beneficial interest required, with no rounding adjustment — exactly 75% means 75.00% (not 74.99%).

For supermajority calculations on MAJORITY OF QUORUM (regular, bylaw amendment, special assessment), the threshold is computed by applying the supermajority percent to the greater of (a) the effective quorum percent or (b) the actual votes counted. This is a conservative interpretation; the calculator uses the same approach as the California Davis-Stirling reference calculator.

Sources

Last reviewed: 2026-05-16 against:

• M.G.L. c.183A § 6(a) (common-expense liability allocated by beneficial interest).
• M.G.L. c.183A § 10 (organization of unit owners; trustees' powers and meeting procedures).
• M.G.L. c.183A § 11 (master-deed amendment — 75% of beneficial-interest minimum for material amendments).
• M.G.L. c.183A § 17 (special-assessment authority allocated by beneficial interest).
• M.G.L. c.183A § 19 (termination of condominium — near-unanimous consent).
• Trustees of the Cambridge Point Condominium Trust v. Cambridge Point, LLC, 478 Mass. 697 (2018) (master-deed and trust-document interpretation under c.183A).
• Tosney v. Chelmsford Village Condominium Ass'n, 397 Mass. 683 (1986) (interpretation of master-deed amendment provisions; member-approval thresholds).
• CAI New England chapter practitioner reference materials (Massachusetts condominium voting procedure).