Boston Real Estate Development Activity: Trends in the Construction Pipeline

Introduction

Boston’s construction pipeline is booming, with a vast array of projects in various stages of development within a 12-mile radius of downtown. According to a recent dataset of projects in this radius, there are over 400 development projects planned or underway, totaling more than 75 million square feet of new real estate. This pipeline encompasses everything from high-rise office towers and life science labs to multifamily residential communities and hotels. In absolute terms, Greater Boston’s pipeline is among the largest in the nation – Boston leads major U.S. markets with roughly 16 million square feet of office projects alone under construction, a figure that is three times the U.S. average and second only to Austin in relative scale. These robust real estate trends in Boston highlight the city’s continued growth as an economic and innovation hub, even amid national development headwinds.

Overview of the Development Pipeline

Boston’s development pipeline reflects a healthy mix of active construction and future projects. Out of the ~401 projects identified, about 35% are under construction, while the majority (roughly 61%) are still in planning/proposal stages, with a small remainder in final planning approvals. In other words, for every project currently being built, there are nearly two more in the proposal stage waiting to break ground. This indicates a substantial Boston construction pipeline poised for the coming years, though many planned projects could be contingent on market conditions and permitting. The high ratio of proposed projects suggests developers are positioning for future demand, even if not all proposals will immediately move forward.

Notably, the pipeline is not confined to Boston’s downtown – it spans a 12-mile radius, encompassing active development in close-in cities like Cambridge, Somerville, and Quincy, as well as inner suburbs. Many of these areas are experiencing a spillover of Boston’s growth, with new projects clustered around transit hubs (such as the MBTA stations) and emerging districts (e.g. Somerville’s Union Square, East Cambridge’s Kendall Square, and the Boston Landing/Allston area). Overall project volume is high, and Boston’s recent pace of construction has been record-setting: nearly 6.2 million square feet delivered in 2023, with an expected 9.9 million in 2024. Despite some economic uncertainties, developers remain optimistic about Boston’s long-term fundamentals, fueling a large pipeline that should reshape the region’s skyline in the mid-2020s.

Types of Developments: Residential, Office, and Mixed-Use

Residential development dominates the Boston pipeline by sheer number of projects. Approximately 228 projects (over half of the total) are residential, primarily multifamily apartments. This reflects Boston’s pressing demand for housing – from luxury high-rises downtown to mid-sized apartment buildings in neighborhoods and suburbs. Many of these residential projects also include ground-floor retail or are part of larger mixed-use plans, integrating homes with shops and public spaces. The next largest category is office and lab projects (around 80+ projects), underscoring Boston’s strength in the tech and life science sectors. In fact, about 60% of new office construction in Boston is conceived as lab space to support biotech and pharma firms. Key innovation clusters like the Seaport, Kendall Square, and Waltham’s 128 corridor are hotbeds for new lab-enabled office buildings. Beyond offices, the pipeline features 33 hotel developments (hospitality projects), indicating confidence in the region’s tourism and business travel rebound. There are also around 20 retail projects (many of which are smaller shopping centers or retail components of mixed-use developments) and a similar number of industrial/flex projects (including last-mile distribution centers and specialized R&D facilities).

A rendering of South Station Tower, a 51-story mixed-use skyscraper under construction above Boston’s historic South Station. This transformative project will add 685,000 sq. ft. of office space and 166 luxury condominiums to downtown.

South Tower Station

Importantly, a significant trend is mixed-use development. Rather than single-purpose buildings, many of Boston’s biggest projects blend uses to create new urban hubs. For example, the South Station Tower (pictured above) is a landmark project combining offices, transit infrastructure improvements, and Ritz-Carlton branded residences in one 1-million-square-foot complex. Similarly, the ongoing redevelopment of Cambridge’s CambridgeSide mall area includes both an office tower and a residential building on the former mall site, integrating new housing into a traditional retail center. We also see former industrial sites being transformed into mixed office/lab and residential campuses (as in Somerville’s Assembly Square and Allston Yards developments). This mixed-use approach aligns with modern urban planning trends, creating 24/7 neighborhoods where people can live, work, and shop in proximity.

Life science facilities deserve special mention as a subset of commercial development. Boston’s reputation as a global biotech hub is driving numerous lab projects (often categorized as office or flex in data). For instance, Somerville’s Boynton Yards and 74 Middlesex (“74M”) projects are delivering hundreds of thousands of square feet of laboratory space to meet biotech demand. Even traditionally residential or academic areas like the Longwood Medical Area are seeing major new research buildings (e.g. the 1.7 million sq. ft. Longwood Place project). These developments frequently incorporate office and retail components as well, reinforcing the mixed-use trend. On the other hand, pure retail development in the pipeline is relatively limited – only a handful of new retail centers are planned, and most are smaller in scale. This reflects the national cooling in brick-and-mortar retail expansion. Instead, retail is often included as a component within larger projects (for example, a new grocery store at the base of an apartment building).

3 Star Office, Suburban

Surge in Residential Projects: Unit Counts and Sizes

The housing pipeline in the Boston area is robust, ranging from modest infill projects to massive redevelopments. Residential developments in this 12-mile radius include everything from 20- to 50-unit apartment buildings filling small parcels, up to skyscraping residential towers with well over 150 units. A typical new apartment project in the city might have on the order of 50–150 units, often built as mid-rise or high-rise construction. For instance, one planned complex in Brookline, 1180 Boylston Street Residences, is expected to deliver about 50 units of housing in a mid-sized building. On the larger end, the Ritz-Carlton Residences at South Station Tower will comprise 166 luxury condominium units atop a mixed-use tower. And in Charlestown, the Bunker Hill Housing Redevelopment (Phase One) – one of the largest residential projects in the pipeline – is a multi-phase effort replacing aging public housing with modern mixed-income housing. Phase One alone is approximately 2.84 million square feet of development, which will translate to several hundred new apartments when complete.

In terms of unit sizes, most new apartments are designed to be relatively space-efficient, catering to a mix of single professionals, couples, and small families. Typical unit layouts in Boston’s new developments range from studios around 450–500 sq. ft. up to two-bedroom units around 900–1,000+ sq. ft., with luxury units (and condos) often larger. Across many projects, an average unit size around 800–1,000 sq. ft. can be inferred, suggesting a focus on one-bedroom and junior two-bedroom units which are in high demand. High-end developments may skew larger – for example, the Ritz-Carlton condos (geared toward the luxury market) include sprawling 3-bedroom residences and penthouses, pushing average unit sizes well above 1,500 sq. ft. Conversely, some transit-oriented or workforce housing projects emphasize smaller units (micro-studios and one-bedrooms) to maximize affordability and density. Overall, the pipeline is adding thousands of new residential units to the region: by extrapolation, the 37.6 million square feet of multifamily space planned could equate to roughly 30,000–40,000 new housing units in total over the coming years, a significant infusion aimed at easing the area’s housing shortage.

4 Star Office, Suburban

It’s also worth noting the amenities and quality of these residential projects. Many fall into Boston’s top-tier “4-5 Star” building quality categories, meaning they feature modern amenities like fitness centers, co-working lounges, roof decks, and concierge services. Developers are clearly targeting the upper end of the market in many cases (to justify high construction costs), though there are also affordable and mid-market projects in the mix, often spurred by inclusionary zoning requirements. The emphasis on mixed-use means residents in new buildings often enjoy on-site retail (cafes, grocery stores) or nearby commercial conveniences, enhancing the appeal of these units despite their generally compact size. In summary, the Boston real estate development activity on the residential side is delivering a broad spectrum of housing – but with a common theme of higher density, modern apartment living designed to attract both young professionals and downsizing empty-nesters who want to live in amenity-rich, transit-accessible locations.

Sustainability and LEED Certification Trends

Sustainable design is a priority for many Boston developers, but the prevalence of formal LEED certification in the current pipeline is somewhat limited based on recorded data. Only a small fraction of projects (on the order of 2% of the pipeline) are currently listed as pursuing or having obtained LEED certification. A handful of high-profile developments have announced targets of LEED Gold or Platinum. For example, Somerville’s Boynton Gateway lab building has been designed to achieve LEED Platinum status, incorporating cutting-edge green architecture and wellness features. In Boston’s Seaport, the upcoming 74M life science tower by Greystar is likewise targeting LEED Platinum (as well as WELL Platinum), with numerous eco-friendly systems and a high-performance building envelope. And the South Station Tower downtown is being built to LEED Gold standards, along with advanced wellness and energy certifications (WELL Gold and BREEAM) as part of its design objectives.

Overall, while only 7 projects in the pipeline explicitly list a LEED certification level (ranging from Certified up to Platinum), many more are likely following Boston’s stringent green building policies in practice. The City of Boston has aggressive climate goals – including a push for carbon-neutral buildings and a BERDO emissions reporting ordinance – which encourage new developments to adopt sustainability measures even if they don’t pursue the costly process of LEED certification. Thus, features like energy-efficient HVAC systems, solar-ready rooftops, rainwater management, and use of recycled materials are increasingly standard. We see several all-electric buildings and proposals incorporating mass timber or other low-carbon construction techniques in the region, reflecting a broader commitment to sustainability beyond just the LEED label. In sum, the prevalence of LEED in the data (only ~1–2% of projects) likely understates the true emphasis on green design. Many developers are building to LEED-equivalent standards or better, even if they don’t end up obtaining the plaque. Going forward, as Boston continues to prioritize resilient, low-carbon growth, we can expect more of the pipeline to achieve formal green building certifications or meet stringent environmental performance benchmarks.

Pre-Leasing Activity and Market Dynamics

A notable aspect of Boston’s development pipeline is the strong pre-leasing activity for certain high-profile projects, especially in the office and life science sector. In fact, a number of the largest new office buildings have secured major tenants well in advance of completion – a testament to Boston’s flight-to-quality in the office market. For example, the One Congress tower (a 1 million sq. ft. office high-rise delivered in late 2023) was fully leased at delivery, anchored by State Street Corporation’s new headquarters. This 43-story trophy tower reached 100% lease-up roughly a year before opening, illustrating that companies are willing to commit early to best-in-class space. Another example is 1001 Boylston St. in the Longwood area, a lab-capable office building where most space was pre-leased to non-biotech firms ahead of its 2024 completion. These cases show that premier locations and amenities can attract tenants even in a competitive market. As a result, about 18% of the pipeline projects (roughly 72 projects) report being 100% pre-leased – many of these are build-to-suit offices, medical facilities, or public-sector developments that had tenants (or buyers) lined up from the start.

On the other hand, speculative developments (projects built without committed tenants) are facing a more cautious leasing environment, especially in the wake of the pandemic and shifts in office demand. Many proposed office buildings currently show 0% pre-leasing, and even some under-construction towers are only partially leased. A prominent case is the South Station Tower: as of mid-2025, this 51-story downtown project (due in 2025) had only secured its first office tenants – law firm Jones Day (41,000 sq. ft.) and insurer FM Global (~50,000 sq. ft.) – representing just around 15% of its 685,000 sq. ft. of office space. The remaining majority of space is still available, reflecting a more gradual lease-up for even a marquee development launched on speculation. Similarly, other new towers like Winthrop Center in Downtown Crossing, completed in 2023, remained about 35% vacant as of early 2024. These examples underscore a bifurcation in the market: top-tier “trophy” properties are attracting tenants (often from older buildings) in a flight-to-quality trend, while second-tier projects or those in saturated submarkets may lease up more slowly.

Pre-leasing is also relevant in the industrial/logistics segment, though Boston’s pipeline there is modest. A few planned warehouses and distribution centers have been pre-leased to e-commerce companies (for instance, Amazon’s new 707,000 sq. ft. distribution facility in Boston was fully leased to Amazon itself). In the multifamily residential realm, “pre-leasing” typically refers to leasing units a few months before a building opens. Most large apartment projects in Boston do engage in pre-leasing campaigns, but occupancy is generally assumed to fill up post-completion, so the dataset doesn’t list a percent leased for residential projects until they open. One could say the equivalent trend is strong presales in condo developments – e.g., pre-sales have begun for the Ritz-Carlton condos at South Station Tower in anticipation of high demand for those 166 luxury units.

In summary, pre-leasing activity in Boston’s development pipeline is a mixed picture: many high-value projects enjoy significant commitments (some 100% leased well ahead of time), highlighting confidence in Boston’s key sectors like finance, tech, and life sciences. At the same time, the overall volume of new space – particularly speculative office and lab projects – is high, and leasing has become more challenging for those without an anchor tenant. Market observers note that Boston is experiencing a “historic wave of new supply” in offices, which, combined with evolving work-from-home trends, has introduced some leasing risk. Still, Boston’s diversified economy and status as an educational and innovation center give it an edge; tenants are selectively taking prime space, and developers are cautiously optimistic that real estate trends in Boston will remain favorable. In the long run, the extensive pre-leasing of marquee projects suggests that demand for quality space is indeed present, even if backfilled by tenants relocating from older stock.

5 Star Hi-Rise Apartments Condo - South Station

Outlook: A Transformative Building Boom

The current development pipeline around Boston signals a transformative building boom that will shape the region’s urban landscape for years to come. Dozens of new skyscrapers and campus-style developments are slated to add new office clusters, thousands of housing units, and refreshed commercial hubs. In downtown Boston alone, projects like the South Station Tower and Winthrop Center will redefine the skyline, while in the suburbs, large mixed-use projects (such as the redevelopment of former malls and industrial yards) will create new live-work-play districts. The prevalence of residential projects in the pipeline is a promising trend for a region that has long struggled with housing supply – if even a portion of the ~30-40k envisioned new units come to fruition, it could help moderate housing costs and support the city’s growth. Likewise, the heavy focus on lab and innovation space should keep Greater Boston at the forefront of the life sciences and tech industries, providing state-of-the-art facilities to retain and attract companies.

That said, the road ahead is not without challenges. Rising interest rates, construction costs, and community opposition (NIMBYism) can all slow down or halt projects. We already see that many pipeline projects are still in “proposed” status, and some may not break ground on their original timelines. Boston’s office market is also in a period of flux, balancing an influx of new space with evolving tenant needs – which could lead to a short-term oversupply and higher vacancies until growth catches up. City officials are encouraging adaptive reuse (such as office-to-residential conversions) to address these imbalances, which might further change the composition of development activity.

Nevertheless, the overall picture of Boston real estate development activity is one of vibrancy and adaptability. Developers are clearly betting on Boston’s fundamentals: world-class universities, a talented workforce, robust healthcare and tech sectors, and improving transit-oriented urban planning. The pipeline’s breadth – spanning ultra-luxe condos, affordable apartments, gleaming office towers, hotels, labs, and retail – speaks to a balanced growth strategy for the metro. If economic conditions remain reasonably stable, Boston’s construction pipeline will deliver a wave of modern, sustainable buildings that both meet current market demands and chart a new course for the city’s future. In a few years’ time, residents and visitors will be able to point to new skyscrapers, revitalized neighborhoods, and expanded skylines as the tangible results of today’s development trends. Real estate trends in Boston continue to evolve, but one thing is certain: the city’s built environment is on the cusp of significant change, driven by an ambitious development pipeline that is among the most active in the country.

3 Star Industrial Distribution

Sources: CoStar Boston Development Pipeline data (2025); The Stevens Group/CoStar Boston Office Market Report; Bisnow Boston Real Estate; SGA Architecture News