Maryland ADU Guide is built around a simple standard: if a homeowner could make a planning, permitting, or financial decision based on something we publish, the information should be traceable, clearly scoped, and as current as we can reasonably make it.
Our source hierarchy
We prefer primary government sources over summaries from builders, blogs, forums, or commercial websites. Depending on the topic, our research may include Maryland statutes and legislative records, Maryland Department of Planning materials, county and municipal zoning codes, planning department guidance, permit instructions, fee schedules, building-code resources, maps, meeting records, and other official publications.
Secondary sources may help us discover questions, edge cases, terminology, or homeowner concerns, but they are not our preferred authority for a regulatory claim when an official source is available.
How we add value
We do not aim to reword government pages or reproduce competitor articles. Our goal is to add information gain through comparison, organization, interpretation, decision support, and practical tools. That can include jurisdiction-by-jurisdiction rule matrices, calculators, checklists, permit workflows, cost breakdowns, source-linked timelines, and explanations of where statewide and local requirements interact.
Local rules are treated as local
Maryland ADU requirements can involve both statewide law and local implementation. We avoid assuming that one county’s procedure applies to another jurisdiction. When a rule is local, we identify the jurisdiction and source as clearly as possible. When a point cannot be confirmed from the available official material, we would rather state the uncertainty than present a guess as a fact.
Updates and review dates
Regulations, fees, forms, department procedures, and local ordinances can change. Time-sensitive resources should indicate when they were reviewed or updated. A review date means we checked the page against the sources available at that time; it does not guarantee that a government agency has not changed a rule or procedure afterward.
Dates mean different things
We keep three dates separate when they matter: last independently verified is when we checked the regulatory claim against the cited official source; page updated is when we edited the webpage; and effective date is when the law, ordinance, or rule took legal effect. Editing a page does not reset its verification date.
For regulatory pages, we use a small set of status labels consistently: Enacted for a rule we verified as currently effective; Transition when an existing framework remains relevant while implementation is changing; Proposed for a measure not verified as enacted; Legacy for older published rules that may remain relevant during a transition; and Source conflict when official records do not support one reliable answer. We do not treat a proposal as law.
Corrections
If we identify a material error, we aim to correct it promptly and update the affected resource. Readers, planners, officials, contractors, and homeowners are welcome to send us a source or correction for review. We do not change factual conclusions merely because a company or individual disagrees with them; supporting documentation matters.
Firsthand experience and expert review
We do not claim firsthand Maryland permitting, construction, legal, architectural or engineering experience that we do not have. When a page includes firsthand field experience, a homeowner case, professional interpretation or expert review, we aim to identify the source and attribute that experience clearly rather than presenting it as our own.
When a qualified professional reviews a resource, the reviewer should be named and the scope or date of that review should be stated. A professional review does not convert the entire site into professional advice, and we do not use credentials or reviewer labels that cannot be verified.
Use of AI and automation
AI tools may assist with research organization, drafting, editing, table creation, data normalization, quality checks, or the development of planning tools. They are not treated as an authoritative source for Maryland law or local zoning. Regulatory claims are expected to be grounded in the underlying source material and reviewed before publication.
Commercial relationships
Maryland ADU Guide may eventually earn revenue through advertising, referrals, partnerships, digital resources, or other commercial relationships. When a relationship could reasonably affect how a reader interprets a recommendation, we intend to disclose it clearly. Payment does not buy a favorable regulatory conclusion or the alteration of an official requirement.
What we do not claim
Maryland ADU Guide is an independent publication, not an official government resource. We do not represent that our content replaces a zoning determination, permit review, survey, title review, legal opinion, architectural plan, engineering analysis, contractor estimate, tax advice, or other professional service specific to a property.
Put the research to work
Return to My ADU Plan → to choose your next property check. If you found an outdated statement or a stronger official source, use the correction instructions and include the page link.