Questions / Answers
Q: Why does the Jury recommend to get rid of the fourth level balcony and the daylight window in the backstage area of the Main Stage?
A: When determining the configuration of the MH, the acoustic parameters set out in the competition documentation and Jury recommendations, i.e. sound and view, must be ensured. According to the client of the Riga Philharmonic, this hall should have two balconies (marketing strategy). The balcony of Level 4 should have an inclination of at least 45 degrees.
The Jury unanimously agrees is that the daylight window behind the organ may serious challenge good sound distribution in the hall. The client and the Jury agree that the competitor must prove the feasibility of the proposed solution with calculations, indicating also the type of organ to be provided in the proposal. If there is a good solution for daylight in the concert hall, then it will be seen as an advantage.
Q: Is it possible to submit physical models in the second competition round?
A: The Competition Brief of the Riga Philharmonic does not have such a provision, however, the submission of additional materials is not prohibited.
Q: And would it be possible to present the solutions prepared in the second round to the Jury in person?
A: The solutions prepared in the second competition round are not expected to be presented in person to the Jury until the making of the Jury’s decision.
Q: Please specify the details of the 3D model to be submitted in the 2nd competition round – should it be only the exterior model of the Riga Philharmonic building or should it show the interior as well?
A: According to the Competition Brief:
7.3.4. 3D deliverable with minimum requirements:
7.3.4.1. A model of acoustic calculations for the Riga Philharmonic and a report on the calculations of acoustic parameters, charts showing them and a description of the materials used.
7.3.4.2. A combined 3D model of the Competition Object in .ifc format (LOD 200), choosing meters (m) as a unit of measurement and adding textures and materials used to the model. 7.3.4.3. The model must clearly reflect the construction intention, integration of the building into the surrounding environment: its location and dimensions (length, width, height, construction area and volume).
Q: Please specify what must be included in the AVK (heating and ventilation) and BK (building structures) solutions of the 2nd competition round? Would this be in the form of an explanatory description?
A: The solutions of the 2nd competition round must include the location diagram of the main ventilation equipment and main networks, the explanatory description of how air supply/exhaust/cooling is provided in the MH, and what are the AVK solutions in the stage area. As regards the BK part, the explanatory description should explain how it is intended to transform the existing building substance, how the new additions will be integrated while respecting the existing building. Anchor points for technological loads must be considered.
Q: Is it allowed to increase the height of the building (the allowed limit is 24 m) in the historic centre of Riga? Or is it necessary to amend the proposal in such a way that the height of 24 m is not exceeded?
A: The part of the building exceeding 24 m will have to be approved as a deviation with the responsible institutions of the city of Riga, however, a kind of encouragement has been received from the National Cultural Heritage Board (NCHB), namely, that, taking into account the special importance of the Riga Philharmonic building, such architecturally justified deviations would be permissible.
Q: What level of detailing should have the lighting and sound technology solutions at this stage? The location of what systems must to be indicated?
A: Submit proposals for the placement of stage lights and audio equipment (and room sizes to accommodate technological solutions – technical ceilings, stage lifts) in the Main Hall and in the Small Hall. Also take into account other equipment (upper machinery), e.g. sound reflectors, possible screens, etc. The position of stage lift units on the stage must be specified as indicated in the Brief and guidelines. The effect of their size/amount on the floor/ceiling plan must be shown, so that it can be ensured that the solution will not affect the size or functionality of other rooms.
Q: Section 5 “The Acoustics of the Hall” of the “Jury’s Recommendations for the Entries Selected for the 2nd Competition Round” asks the teams to prepare “speech intelligibility – RASTI calculation and assessments for the Main and Small Halls”.
- Is this necessary? RASTI assessments are heavily dependent on the technical design of the electronic sound system used within the hall and as such would not be something we would do at the competition stage.
- As we are only preparing acoustic modelling for the Main Hall space, if the RASTI calculation is required, would it be acceptable to only submit it for the Main Hall space?
A: RASTI (Speech intelligibility) is voice intelligibility of room acoustics and its assessment and calculations should also be provided for the Small Hall.
FOR INFORMATION: Section 5 “The Acoustics of the Hall” of the “Jury’s Recommendations for the Entries Selected for the 2nd Competition Round” should read as follows:
The aim of the Riga Philharmonic project is to obtain the values of acoustic parameters in the audience seats/performer places at 500–2000 Hz.
| T30 occupied, mid-frequency reverberation time, sel. | Lateral Energy Fraction LF | Clarity, C80, in dB | Early support, dB | |
| T30 | LF | C80 | STearly | |
| Criteria maximum | 2.2 | 3.0 | ||
| Criteria minimum | 1.9 | 0.2 | -2.0 | >-12 |
| Example: Vienna Grosser Musikverinsaal | 2.0 | 0.17 | -2,0 |
To meet the requirements set out in Clause 7.3.4.1. of the Brief, the proposals for the Main Hall as part of the 2nd competition round should contain the following information:
– the overall geometric dimensions of the hall (width, depth and height, profile angle of the elevation of the stalls) and cubic capacity of the hall;
– dimensions of the stage revolving platform, the correspondence of its width and depth, the solution of the choir balcony behind the stage, the angle of the side planes of the stage;
– indicate which organ would be more appropriate for the geometry of the specific hall, taking into account its cubic capacity and dimensions;
– indicate dimensions and volume of the Organ room;
– show the geometry of the main 1st and 2nd balconies, and the side balconies;
– indicate the areas (zones) of the planned absorbent and dispersive materials;
– show design principles for integrating the organ and the reflectors into the design of the hall; in order to illustrate how a degree of acoustic flexibility is to be accommodated by their design;
– show appropriate wall thicknesses (to illustrate where existing fabric is to be retained) and clearly illustrate the extent of the acoustic envelope.
The model for the calculation of the hall provided for the 2nd competition round must reflect the following acoustic quality parameters:
a) T30, calculated reverberation time
d) Early Lateral Energy Fraction LF
e) Clarity, C80
f) RASTI
g) STearly
indicating the characteristic points for performing calculations and the reflection of the calculation schedule with a breakdown by frequencies (125)/250/500/1000/2000/(4000) Hz for each point respectively. For calculations, in addition to the standard optional points, make calculations of the rear wall of the stalls under the first balcony in the corner area of the hall and in the choir balcony area behind the orchestra. Prepare Speech intelligibility – RASTI calculation and assessment for the Main and the Small Halls.
Q: Are the exact dimensions of the stage essential or is it enough to provide the necessary functions?
A: The dimensions of the stage must be provided as required in the Designing Programme. It is essential to stick to the specified size, layout and functionality of the stage and stage technologies as described in the Brief and in our final guidelines of the first competition round. Each area on the stage has a specific and important meaning. It also refers to the parts of the stage which can be raised.
Q: Do both cargo lifts have to connect all floors? Can one of them connect only the delivery level with the stage level of one hall?
A: Preferably, the two large lifts should serve all floors where the large residents are located or where there are large spaces for a larger number of visitors. But it needs to be seen in the context of the location of rooms and residents in the building. Cargo lifts ensure transportation of large or oversized items. If the rooms on upper floors are not intended for residents and are only used as offices with a small load of daily technological cargoes, then there may be only one cargo lift for each upper floor. A separate transport lift must be provided for the MH and the SH.
Q: Why does the JVLMA room (D5-2) need a ceiling height of 6m?
A: The indicative ceiling height is the optimal height specified by the residents to ensure the acoustic parameters of the room for the particular function and sound production requirements. If it is suggested to change the height of the room, the proposed change of height must be justified, and approved and commented on by an internationally recognized professional acoustician, based on the specific characteristics of the particular room and its type of use.
Q: What is the average number of cars entering/leaving the territory of the Ministry of Foreign Affairs of the RL on a daily basis? For what number of cars are there parking spaces provided in the territory of the ministry?
A: The car park of the Ministry of Foreign Affairs is used to the limit permitted by the area of the plot of land
Q: Considering the possibility of significantly improving the functionality of the building on its SW side, and cutting the existing trees for this purpose – could the sketch design receive a reduced score as a result?
A: Cutting of trees in the area of the historic centre of Riga may be permitted in exceptional cases. If it is necessary for the project solutions, the author/s of the project must justify the necessity of cutting trees in the explanatory description.
Q: Is it permissible to have the height of the multifunctional hall on one floor, i.e. approx. 3m, providing sufficient acoustic comfort?
A: 3m is an insufficient height. The SH must comply with the acoustic requirements of LBN 016 -15 for a multifunctional hall.
Q: Can the height of the Small Hall and the Rehearsal Hall be defined according to acoustic calculations?
A: Yes, according to the Brief. The building standard LBN 016-15 determines the requirements for the Small Hall (as a universal hall), but it does not lay down the requirements for the rehearsal hall, however, the parameters of the room must meet the client’s requirements.
Q: Does the Rehearsal Hall require access from visitor areas?
A: It is not required, yet it provides the user with an option of using additional rooms.
Q: Is the original blueprint of the building available? Would it be available in the 2nd competition round or at the start of the designing works?
A: The reconstruction project of the Congress House will be available when the designing works start.
Q: Since the existing building will have to undergo significant reconstruction, in order to ensure the safety of the existing structures, a complete survey of the existing structures will have to be carried out at the designing stage (including a thorough examination of the existing structures – documents and on-site inspections of the parts of the building and structural calculations), so that the designers could take responsibility for the structural condition. Should this scope of works be included in the proposal or will it be organised differently?
A: At the start of the designing works, an in-depth technical survey should be carried out, which should be included in the scope of works to be performed.
Q: Does the medical centre meet the requirements set by the client for the participant of the competition as an important public object and a public building?
A: A medical centre with a total area of at least 7,000 m² and with public functions qualifies as a similar important public object and a public building.