BIM Modelling – a Useful Tool for the City of Helsinki

The City of Helsinki encourages the use of building information modelling as it enables the city to acquire more and better information on its properties and to maintain them more easily. Thus, the city is gradually shifting to BIM modelling, in both new build and refurbishment projects.

The City of Helsinki Public Works department has its own Architectural Division with a current staff of 14. The principal part of the Architectural Division’s work is commissioned by the city’s Real Estate Department, which is responsible for the city-owned buildings and their maintenance. The Architectural Office uses ArchiCAD software and BIM models have already been employed since the turn of the millennium. In order to tackle the Kivikko central kitchen pilot project the staff of the Architectural Office brushed up their skills by attending a tailored BIM modelling course. Although all the architects were fluent with ArchiCAD, there was also much that was new to be learnt on the course. According to architect Jaakko Haapanen, the most rewarding content of the course was learning a new mode of teamwork that will certainly be very useful in the future.

BIM models benefit the city

The City of Helsinki Real Estate Department encourages its subcontractors to exploit BIM models. Real Estate Manager Jukka Hovi of the Real Estate Department asserts that BIM models are particularly useful as visual tools: even non-professionals can understand 3D models. This is a particular advantage in major projects that concern and interest all Helsinki residents. Hovi identifies as the major technical advantage of BIM models collision detection, which helps to avoid unnecessary design faults, as the designs of various designers can be merged.

The models also come in handy in cost estimating. Hovi points out that one of the advantages of BIM models is the mass and quantity data they provide. For example, in the Kivikko central kitchen project, the BIM model was used to calculate the project cost estimate already at the planning stage. Thus the budget could be estimated prior to the implementation decision. In addition, the ease with which the cost estimate can be imported from the BIM model enables the scheme to be adjusted until the price suits the developer and the design is acceptable to the designer.

BIM model of the planned Kivikko central kitchen.

“In an ideal situation the BIM model would send a reminder when it requires maintenance or repairs,” says architect Jaakko Haapanen jokingly. For the time being this is not the case; the maintenance of buildings requires active involvement. To facilitate the use of BIM models in the maintenance of buildings, too, the Real Estate Department is involved in the KIHU project (property maintenance and repair information models and databases) run by TEKES, which is Finnish publicly funded expert organisation for research, development and innovation in. The project focuses on devising methods for the flexible transfer of information exchanged by design, construction and maintenance operations from one stage of the building’s life span to the next. Based on experience, it is justified to state that BIM modelling has increased the efficiency of information flow in particular between the design and construction operations, where data on spaces, building elements and systems are added as the modelling progresses from one stage to the next. When the best operating policies for BIM-based property maintenance are established, the City of Helsinki will adopt the system.

Common ground rules

For the time being the Real Estate Department has not made a policy decision to adopt BIM modelling on a comprehensive basis, as it so far lacks the capacity to receive all plans and designs as BIM models. As an example, all the collision detection reviews are commissioned from outside consultants due to lack of resources. So far the exploitation of BIM models depends on the expertise and initiative of individual project leaders.

As the City of Helsinki Real Estate Department is one of the biggest property owners in Finland, employing many outside consultants in construction projects, it is vital that it receives consistent BIM models from its subcontractors. It is therefore particularly important to agree on common ground rules – BIM guidelines. The Real Estate Department is involved in the Building Information Group’s COBIM project with stakeholders from varying fields of the construction industry. The project’s objective is to update the BIM guidelines published by Finnish government’s Senate Properties in 2007 to comply with current technologies and the needs of all stakeholder groups. Since the publication of Senate Properties’ guidelines, software has become more sophisticated, so that more can be demanded of it in the guidelines. The aim of guideline development is to meet the requirements of developers, contractors and public sector clients alike. The goal of the project is to achieve a national BIM guideline that satisfies all stakeholders.

BIM modelling at the Architectural Office

The City of Helsinki Architectural Office is running several BIM modelling projects concurrently. Projects underway at present include the Kivikko central kitchen and the refurbishments of Meritähti Day Care Centre and Meilahti Primary School.

The Kivikko central kitchen has been a pilot project of the Architectural Division, the aim being to exploit the BIM model as efficiently as possible. The central kitchen prepares the daily meals for Helsinki’s hospitals and services centres for the elderly. Production volumes are considerable, the menu varies from day to day, and the whole production process is highly demanding in terms of logistics and hygiene. This is also something that lead designer Jouko Piilola had to consider in his work: the space requirements differ significantly from those of standard industrial kitchens.

In the project piloting has focused particularly on the data that can be extracted from the BIM model. The BIM model has been used to calculate a cost estimate based on the project plan. Final cost estimating was commenced in July. The kitchen should be completed in 2014.

As the estimated cost is calculated on the basis of the model, it means that the project should be modelled roughly even before the final approval of the project plan. Modelling should, however, not be too cursory, as this will affect the quantities calculations. It is therefore desirable to do a good job from the very beginning. The Architectural Division’s policy is to supply future preliminary project plans as a BIM model so that cost calculations can be made on the basis of the model.

However, the model may be amended even after the approval of the project plan to meet client requirements. For example, architect Päivi Halme has updated the project plan for the Meritähti Day Care Centre after the project planning stage in order to cut costs. Mikko Soininvaara, the architect responsible for IT at the Architectural Division states that, “the superiority of BIM modelling lies in the easy amendment of plans and designs after they have once been properly executed.”

Meritähti Day Care Centre in Vuosaari under renovation.

As yet, the Architectural Office has not utilised BIM models on-site, even though they have been available. The city employs outside contractors and has not required them to use BIM models. Hopefully, models will also be utilised on-site; they do facilitate the perception of the work at hand and prevent unnecessary confusion. In addition, BIM models can be used for project scheduling and collision detection.

At the moment architects send off their designs to the work site as 2D drawings. In certain projects, such as the wisent enclosure at the Helsinki Zoo, the BIM model was exploited by delivering the structural drawings to the site as axonometric drawings, which are considerably more illustrative than the conventional ones. It is hoped that in the future BIM models will be in active use on sites, making prints obsolete.

Refurbishments simplified

The majority of work carried out by the City of Helsinki Architectural Office are renovations and refurbishments. The office staff are pleased with the new ArchiCAD renovation tools. The new ArchiCAD 15 features even more sophisticated renovation tools, as can be read in the ArchiCAD 15 article in this issue.

The measurement team led by modelling engineer Pekka Wilska also operates in the Architectural Division of the Public Works Department. In their work the team makes use of laser scanning equipment, which the Architectural Office has found efficient in the creation of the initial model. The point cloud provides accurate dimensional data, and spaces can be observed in 3D, making it unnecessary even to send a surveyor on-site, as the point cloud provides all the data needed. Sometimes the point cloud gives more accurate data than a tape measure.

Opening a point cloud directly in ArchiCAD is so far not practicable, as it will open as thousands of individual objects. The Architectural Division therefore extracts the point cloud data with MicroStation software, where it is manually converted into a model, i.e. the points are utilised to position walls and slabs correctly. The MicroStation model is then exported to ArchiCAD for further processing.

Future strategies

In the future the City of Helsinki will increase its investment in BIM modelling. Jukka Hovi of the Real Estate Department thus hopes that designers will recognise BIM modelling as the way ahead: BIM modelling is genuine computer assisted work – not just drafting. Hovi’s vision is to build a virtual BIM model server/project library for the use of the city, which would allow designers to develop their projects and would always provide up-to-date information on the progress of the project. This goal is still some distance away but the direction is right.

Architect Jaakko Haapanen shares Hovi’s views. Both firmly believe that BIM modelling will become established practice in the future. In Haapanen’s view teamwork in the context of a BIM model is a future trend. Team and distance work are becoming more widespread and the software has to respond to this.  One must be able to jump into a project even at the stage when it is in full swing.

This article was published in the 4/2011 issue of ArchiMAG in December 2011.

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