Home Addition Services

Southern New Hampshire

Same-Day Estimates 

Design & Build Services 

Insurance Assistance

Request Lorem Epsom

Hero Request Form

Creating Your Dream Home With Professional Addition Services

Since 2004, CMGC Building Corporation has provided outstanding home addition services throughout Southern New Hampshire and the Lakes Region. Our team of master carpenters brings 40 years of combined experience to every project, creating additions that blend perfectly with your existing home while boosting functionality and property value.


We recognize that home expansion represents a significant investment for your family, which is why we focus on precise craftsmanship, reliable scheduling, and using advanced building materials and methods. Our dedication to performance, integrity, safety, and teamwork helps us consistently deliver results that homeowners love.


As one of just three companies certified for historical renovations in the region, we bring specialized knowledge to every project, from contemporary sunrooms to historically accurate additions.

CMGC Building Corporation offers complete services to make your home addition project smooth and straightforward. Our team handles everything from initial design discussions to securing building permits and completing energy audit documentation. As a family-owned business, we take genuine pride in our workmanship and stand behind our construction with a 5-year warranty on all additions.


We maintain full licensing and insurance, including liability coverage that safeguards your investment. Our GAF and lead certifications demonstrate our commitment to industry standards and safety protocols. From small home offices to complete second-story additions, our dedicated team builds your vision with precision and attention to detail.


Contact CMGC Building Corporation today for same-day estimates on most projects and see how we can enhance your home.

Why Choose Us

A white checkmark icon centered inside a rounded black square.

Liability Insurance Coverage

A white checkmark centered on a black rounded-square background.

Same-Day Estimates for Most Projects

A white checkmark centered inside a rounded black square.

Historical Renovation Works Certified

A white checkmark icon inside a black rounded-square background.

Manufacturer Warranties

A white checkmark centered inside a rounded black square.

Master Carpenters

A white checkmark icon centered on a black rounded square background.

Licensed and Fully Insured

CMGC Building Corporation
A minimalist black icon of a house roof featuring four angled stripes, a chimney, and a small square window.

Attic Remodeling

Discover the untapped potential of your home with attic remodeling by CMGC Building Corporation. We convert unused attic spaces into beautiful, practical living areas that add substantial value to your property. Our approach addresses structural needs, insulation requirements, and lighting solutions to create comfortable spaces perfect for bedrooms, offices, or recreation areas.
A black icon of a double bed next to a nightstand with a lamp.

Bedroom Extensions

Get the spacious primary suite or extra bedroom your family needs with our custom bedroom extensions. CMGC Building Corporation designs and constructs bedroom additions that integrate naturally with your existing home while providing the additional space you desire. Our master carpenters ensure quality craftsmanship from foundation to final details.
A simple line drawing of a small, solid black rectangular room with a door, centered inside a transparent wireframe house.

Four Season Room Additions

Experience nature year-round with a four-season room addition from CMGC Building Corporation. These versatile spaces include energy-efficient windows, proper insulation, and climate control systems for comfort in all New Hampshire seasons. Our design team creates spaces that maximize natural light while maintaining energy efficiency throughout the year.
A black icon of a house with a car parked inside the garage.

Garage Additions

Increase your storage capacity and protect vehicles with a custom garage addition from CMGC Building Corporation. From single-car extensions to multi-bay garages with workshop areas, we build structures that match your home's architecture and fulfill your specific needs. Our team handles all permits and ensures proper installation of electrical systems, doors, and ventilation.
A black icon of a person sitting at a desk with a laptop inside a house outline, representing working from home.

Home Office Additions

Design an ideal work environment with a dedicated home office addition by CMGC Building Corporation. We understand what makes productive workspaces function, including appropriate lighting, sound insulation, and technology integration. Our custom home offices provide the privacy and functionality needed for remote work while adding to your property's overall value.
A simple, black-and-white icon of a house with a gabled roof, two windows, and a doorway.

In-Law Suite Additions

Welcome extended family with comfort and privacy through our specialized in-law suite additions. CMGC Building Corporation designs these spaces with accessibility as a priority, often featuring zero-entry showers, wider doorways, and thoughtful layouts. These suites offer comfortable, semi-independent living while keeping family close and potentially increasing property value.
Black icon of a kitchen scene with a stove, hood vent, drawers, and a refrigerator.

Kitchen Extensions

Create a spacious culinary haven with our kitchen extension services. CMGC Building Corporation skillfully expands your kitchen footprint to accommodate islands, additional storage, dining areas, or premium appliances. Our team coordinates all aspects from structural changes to plumbing, electrical, and finishing work for a cohesive result.
A black silhouette of a couch, a bedside table with a lamp, and a framed picture hanging on a wall.

Living Room Additions

Build the perfect gathering space with a custom living room addition from CMGC Building Corporation. Our designs create open, inviting areas with architectural details that complement your existing home style. We carefully plan traffic flow, natural light, and connections to adjacent rooms to make your new living area truly special.
A black icon depicting a two-story building with a smaller adjacent entrance or extension.

Second Story Additions

Double your living space without increasing your home's footprint through our second story addition services. CMGC Building Corporation manages these complex projects carefully, addressing structural engineering, stairwell design, and roof integration. Our team minimizes disruption to your first floor while creating valuable new space for bedrooms, bathrooms, or multipurpose rooms.
A black silhouette icon of a house with a small attached side structure or awning.

Sunroom Additions

Connect with nature through a beautiful sunroom addition by CMGC Building Corporation. Our sunrooms feature generous windows, quality materials, and strategic orientation to maximize natural light and views while providing year-round comfort. From casual sitting areas to substantial living spaces, we create sunrooms that enhance your lifestyle and home value.
A black icon showing a person standing next to a brick wall with a wrench and hammer crossed above them.

Wall Removal Services

Create an open floor plan with professional wall removal services from CMGC Building Corporation. Our team evaluates structural requirements, identifies load-bearing walls, and installs appropriate support systems before removing barriers. We handle all electrical and plumbing changes, finishing work, and flooring transitions for seamless, open living spaces.
CMGC Building Corporation

10% Off Exterior Upgrades

Transform your home's appearance and energy efficiency with 10% savings on premium siding, windows, and doors from Southern NH's trusted builders.

Contact us today to schedule your free consultation!

Not valid with any other offers or promotions. Restrictions apply.

Must mention this coupon at the time of scheduling.

CMGC Building Corporation

10% Off Exterior Upgrades

Transform your home's appearance and energy efficiency with 10% savings on premium siding, windows, and doors from Southern NH's trusted builders.

Contact us today to schedule your free consultation!

Not valid with any other offers or promotions. Restrictions apply.

Must mention this coupon at the time of scheduling.

CMGC Building Corporation
SAVE ON ROOF & DECK

Protect your investment and enhance your outdoor living space with 10% off professional siding, deck, roof, window, and door upgrades.

Contact our experts now!

Not valid with any other offers or promotions. Restrictions apply.

Must mention this coupon at the time of scheduling.

Recent Projects

An aerial view of a white, crashing wave amidst deep teal ocean water with swirling foam patterns.
An aerial view of a dark, winding river flowing through a dense, lush green coniferous forest.
A close-up view of wind-swept sand dunes, showing rhythmic, rippling textures and soft shadows across a tan surface.
A black icon showing three overlapping speech bubbles, with dots inside the front two, representing group chat or messages.

Here's what our satisfied customers are saying...

At CMGC Building Corporation, we take pride in providing exceptional construction and remodeling services to our customers. We would be grateful if you could share your thoughts about our family-owned business with others. Your feedback helps us improve and helps others make informed decisions. Please take a moment to leave a review of CMGC Building Corporation and let others know what you think.