Every historic preservation project needs a delivery method. The owner has to decide how design and construction services will be procured, how responsibilities will be divided, when contractors will become involved, and when price will be established.
The available methods are not unique to historic buildings. The difference is that preservation and adaptive reuse projects often carry more uncertainty about existing conditions, specialty materials, sequencing, temporary support, code upgrades, and integration of new systems into old construction. Those conditions can make the timing of contractor involvement and allocation of risk especially important.
No single method is right for every project. The owner should choose an approach that fits the scope, level of design definition, schedule, procurement requirements, risk profile, desired owner involvement, and need for early construction input.
Design-bid-build: design first, construction procurement second
In design-bid-build, the owner contracts separately with the architect or engineer and the construction contractor. The design team prepares the construction documents first, and the construction contract is procured after the design is substantially complete. For many public owners, this is associated with sealed competitive bidding and award to the lowest responsive, responsible bidder, although the exact rules vary by jurisdiction.
Design-bid-build is familiar, gives the owner a direct relationship with the designer throughout design, and can work well when the scope is defined with reasonable confidence. Its limitation is that the eventual contractor generally enters after the design is complete. On a historic building, significant discoveries after award can lead to changes in scope, price, or schedule.
Use it when strong design control and competitive bidding are important and early contractor involvement isn't essential. It isn't inherently unsuitable for preservation. A well-investigated, well-documented project can perform successfully under design-bid-build.
Construction manager at risk: early contractor involvement with a separate designer
In construction manager at risk, or CMAR, the owner retains a separate architect or engineer but brings the construction manager into the project during design. The CM can provide estimating, scheduling, constructability reviews, logistics planning, phasing analysis, procurement input, and advice from key trades before the documents are complete. The CM later assumes responsibility for construction, commonly through a guaranteed maximum price or similar commercial structure.
This can be useful where the team needs to evaluate how existing materials will be protected, whether exploratory demolition should occur before final pricing, how temporary support will be installed, or whether major equipment can move through the building. Preserve Signal's adaptive reuse due diligence guide explains why those existing-building questions should be addressed before a project becomes a field problem.
CMAR does not eliminate unknown conditions, and a GMP does not automatically transfer every concealed-condition risk to the CM. Contract assumptions, allowances, contingencies, and responsibility for unforeseen conditions still need careful definition.
Design-build: one entity responsible for design and construction
Under design-build, the owner contracts with one design-build entity for both design and construction. Designers and builders work under the same contractual structure, which can improve collaboration, bring construction considerations into design earlier, and give the owner a single point of responsibility. Design and construction activities may also overlap.
For a historic property, the procurement documents need to define preservation objectives and performance expectations clearly. Character-defining features, treatment standards, material requirements, review processes, and other non-negotiable criteria shouldn't be left ambiguous. The owner may have less direct control over the designer after award because the designer is part of the design-build team rather than under a separate owner contract.
Best-value design-build is a selection approach
Best-value design-build is not a separate contractual delivery method. It is a way to select the design-builder using a combination of technical approach, qualifications, relevant experience, schedule, design quality, management plan, and price, subject to the governing procurement rules.
That approach can matter on preservation work because specialized experience, design quality, team integration, and the approach to existing conditions may be as important as the initial price. Best value ordinarily considers price or cost together with non-price factors. It shouldn't be confused with a purely qualifications-based process.
Design-build bridging: establish preservation intent first
Design-build bridging gives the owner more design definition before responsibility transfers to a design-builder. The owner first retains a design professional to establish the program, design intent, performance criteria, and a defined level of preliminary design. The owner then procures a design-builder to complete the design and construct the project.
This can allow a preservation architect to define critical treatment decisions, character-defining features, material expectations, and other requirements before the design-builder takes over. The risk is over-prescription. If the bridging documents constrain too many details, the owner may lose some of the integration and flexibility that made design-build attractive.
Progressive design-build: develop scope and price with the selected team
In progressive design-build, the owner selects a design-builder early and develops the design, scope, and construction price collaboratively with that team. Rather than asking competing teams to establish a firm construction price from a substantially developed design, the project becomes better defined before the parties reach final construction terms.
That can be valuable when a historic building needs major work but the extent of structural repair, selective demolition, hazardous-material abatement, envelope intervention, or system replacement isn't fully known. Early investigation and specialty-trade input can inform design and pricing. The tradeoff is that cost certainty comes later, so the owner needs transparent cost validation, open-book pricing, negotiation procedures, and an off-ramp if final terms cannot be agreed.
Agency construction management: owner-side management capacity
Agency construction management is an owner-side management service rather than a stand-alone delivery method equivalent to design-bid-build, CMAR, or design-build. The agency CM can help manage design, estimating, scheduling, procurement, stakeholder coordination, construction administration, and other functions, but doesn't ordinarily assume the construction risk a CMAR does.
It can be useful when a public owner has a complex preservation program but needs independent, in-house-style project-management expertise to manage it.
Integrated project delivery: a highly collaborative structure
Integrated project delivery, or IPD, brings the owner, designer, constructor, and sometimes key trade partners into a highly collaborative contractual structure. True IPD commonly includes shared objectives and may include shared financial risk and reward.
It can be valuable on exceptional complexity, but it is less common than design-bid-build, CMAR, or design-build. It requires sophisticated participants, substantial transparency, and contractual arrangements that many public owners do not routinely use.
How the methods compare
- Design-bid-build: separate owner-designer contract; constructor enters after design; often fits a well-defined scope where competitive bidding matters.
- CMAR: separate owner-designer contract; constructor enters during design; useful when early constructability, phasing, and logistics input matter.
- Design-build or best-value design-build: the designer is part of the design-build entity; integration and single-point responsibility are priorities.
- Design-build bridging: the owner establishes early criteria, then the design-build team completes the work; useful when the owner needs stronger early design control.
- Progressive design-build: scope and price are developed with the selected team; useful where uncertainty remains and high collaboration is valuable.
- Agency CM: independent owner adviser; useful when the owner needs additional management capacity under any underlying delivery method.
- IPD: integrated multiparty structure; most suitable for exceptional complexity and a mature collaborative team.
These are common tendencies, not guarantees. Owner involvement, collaboration, price risk, schedule, permitting, and selection procedures depend on the contract, procurement rules, project team, jurisdiction, and project conditions. A delivery method by itself does not guarantee streamlined permitting.
How should an owner choose?
The delivery method should match the project. A relatively straightforward restoration with well-documented quantities and limited unknowns may be well suited to design-bid-build. A complicated adaptive reuse project with structural intervention, phased occupancy, difficult logistics, or uncertain conditions may justify earlier constructor involvement through CMAR, progressive design-build, design-build, or another collaborative approach.
A useful comparison looks beyond contract labels to the practical characteristics the owner needs: collaboration, owner involvement, qualifications-based selection, timing of price certainty, single-point responsibility, and delivery speed. The choice should also follow a historic building conditions assessment and appropriate investigation. A poorly investigated historic building remains poorly investigated regardless of contract structure.
- How well is the scope understood?
- How important is early contractor or trade input?
- How much direct owner involvement and design control is desired?
- Should selection emphasize low price, qualifications, best value, or some combination?
- When does the owner need price certainty?
- How important are schedule compression and a single point of responsibility?
- What delivery and procurement methods are legally available?
For public owners, the final question can determine which options are actually available. State and local procurement laws, grant requirements, funding agreements, and agency policies can limit or prescribe how services are procured. Preserve Signal's historic preservation construction guide provides the broader path from investigation and design through contractor selection and field execution.
Why delivery-method decisions can surface early project opportunities
A decision to use CMAR, design-build, progressive design-build, or an agency CM can create early professional-service scopes before a conventional construction package reaches the market. Procurement planning, owner approvals, selection procedures, feasibility work, preconstruction services, and designer or CM solicitations can reveal a developing project while the approach is still being defined.
Preserve Signal helps firms follow credible preservation and adaptive reuse project signals before formal procurement. Positioning before the RFP explains why visibility and relevant evidence matter before an owner releases a solicitation.
The practical takeaway
Delivery method is not a substitute for investigation, sound contracts, preservation expertise, or project management. It is the structure that determines when the right people can help make decisions and how risks, responsibilities, and price development are managed.
For historic preservation and adaptive reuse, the best choice is the method that gives the owner an appropriate way to investigate the actual building, define non-negotiable preservation requirements, involve construction expertise when it can still influence the work, and comply with the procurement rules that govern the project.